Holy smokes, lots of questions! I'll try to answer them all...
Reese wrote:
when you make a combination of steam powers that performs automatic attacks, what attack bonus, if any, does it use?
for instance, if i used the repeating crossbow + automator + targetor + discriminator + voice command example from the book...
is it using a straight +0 or the attack bonus of the creator/owner?
Sorry, this should have been in the book. I always used the BAB of the coglayer who built the device. That represents his skill in combat, which is transferred via his technical abilities when the device is built. If the coglayer is a PC, I assumed he could continue to tinker with the device as his combat abilities got better, so its attack bonuses increases along with his.
Reese wrote:
and, can a ranger be used to give it a +1 (it looks like it would, but can the rest of the apparatus even manipulate the ranger?)
I'd say that as long as you have the targeter, yes, the ranger could be combined with the rest of the device. The targeter would be the "eye" whose aim is improved by the ranger.
Reese wrote:
also, with the force generator steam power
does the force shield regenerate when damaged by an atempt to penetrate it? and, if so, how often or at what rate?
and, is it possible to reinforce the HP or hardness of the force effect generated, or only the increase in surface area caused by amplifying it?
(come to that, generally, how opaque or transparent is a force effect, anyway?)
In my early games, the force generator produced a true force effect, like a wall of force spell, that was pretty much invulnerable. However, the coglayer player found a number of ways to turn that to an unreasonable advantage, so it had to be changed.

If used as a shield, don't bother to track hp damage to the field. The stats are there just in case the coglayer decides to throw it up in front of his mech's cockpit, and it actually matters whether a steam cannon shot can pierce it or not. But note that the stats for it are just to PUNCTURE it, not to destroy it. So if a steam cannon shot did 34 points of damage (enough to puncture the force generator's 10 hardness and 20 hp to puncture), it would make a hole, but wouldn't actually destroy it. I'd rule that the force shield then closes back up, like the muscular action that closes the guts of a T-rex when the heroes fight their way out of its stomach (see the MM description of pretty much any creature with the Swallow Whole ability). It's practically impossible to destroy the force field (though the mechanical device that generates it is another story).
Reese wrote:
the reason i ask is, i had an idea for a mech with a 100% secured cockpit that used multiple optical orbs protected by force generators to feed a 360 degree view of the battle field to the pilot via a larger size image maker
(something of the GundamWing-style wrap-around monitor)
That's a cool idea. And this is exactly why I added those stats.

Basically, the optical orbs would be immune to any attack that didn't do 31+ points of damage. Any attack that did at least 31 points would pass everything past the 30th point to the optical orbs.
Reese wrote:
and, while i'm at it, about how big is the image produced by a standard image maker, and how does the image area progress as the scale increases?
This never came up in my games. I'd treat it like a regular overhead project (remember from 4th grade?).
Reese wrote:
in some of the official WoTC suplements, there are arcane spells for repairing constructs (the "repair damage" spell line in the "tome and blood" book), how would spells designed for repairing magical constructs function as applied to mechs? for the most part mechs are technological in nature instead of being magical constructs, so i was kind of curious (though, considering the spells repair the same amount of d8 worth of damage as thier cure spell counterparts heal wounds, it would take more than a few of them to fix a broken mech

)
Yes, this is a very good question. I had ideas for "repair mech" spells. But the problem was it would reduce the role of coglayers in the world. The reason for their rise to prominence is that they can build these massive constructs capable of protecting entire civilizations... but if spell casters discover a way to do the same thing for comparable cost, who needs the coglayers? Additionally, there's the game balance implication: as it stands right now, it takes a lot of time and energy to repair a mech. Aside from the mech jockey's patchwork repairs ability, you generally have to stop a mech and spend a long time working on it to actually repair it. If spellcasters can use a standard action to cast a spell, you suddenly have a much, much faster way of repairing mechs -- and, potentially, a radical shift in mech combat, because mechs will be repaired in motion while in the middle of combat.
Based on that, I'd treat the spells that affect magical constructs as being limited to magical constructs. Thus, they might work on some of the magically animated mechs, but no others. I'd also question the motives of any mage who used them. In DragonMech, one of the major bones of contention is the fact that the mages -- who used to be powerful heroes -- are now becoming less important in the face of coglayers and others who use steam technology. Any mage with a normal ego would sneer at a coglayer who needed his help... it would be unlikely that he'd assist someone who is a rival in a larger sense and quite possibly in a more personal sense as well.
Reese wrote:
last question; can steam power users trade devices back and forth, so long as they have free steampowers to support a device, or can they only maintain the devices that they themselves construct?
The last paragraph on page 17 of DragonMech, under the "Steam Powers (Ex)" entry, begins "Each morning..." That paragraph covers the above question in a roundabout way. Coglayers (and other steam power users) are welcome to trade devices back and forth, provided the number of devices maintained by a given coglayer doesn't exceed his normal limit, and provided he has an hour to maintain the devices each morning. Basically, I see that hour in the morning as his "tinkering time" where he makes the traded steam powers his own, becomes acquainted with how they work, and so on. In my game, I'd rule that he couldn't modify traded steam powers until he'd spent an hour tinkering with them. He could USE the traded steam powers, but couldn't build on to them, modify them, customize them, etc. until he spends that hour examining them.
Reese wrote:
BTW, i really like what i see so far, and i can't wait to see more books in this line, though sometimes certain pieces of information seem to be left out (the attack bonus thing, for example)
Glad you like it. Personally, I'm glad there's as little missing as there is. It seems like it would be really easy to translate a campaign setting into book format, but apparently it's easy to leave stuff out.

Reese wrote:
extra weapon mounts increases the mech's PU by 2, but a couple mechs have a base PU that's an odd number (or 50% of the base PU is an odd number)... could extra weapon mounts be designed onto a mech but used to only add one PU instead of 2?
I'd say yes, just halve the cost.
Some mechs also have the heavy payload trait, that raises PU but only for the purpose of cargo (see page 81). One of my early scenarios had the PCs escorting a "dump truck mech" to a mensite mine, which is how that trait came about.
Reese wrote:
for instance, large mechs have a PU of 3... could i add extra weaponmounts to increase it to 4 (since 150% of PU would be 4.5, and an increse of 2 would put the PU at 5, which is more than half again the base PU)
Yes, this is fine. Note that "extra weapon mounts" and "heavy payload" are two different things even though the game effects are similar. Extra weapon mounts represent places to actually mount turrets, guns, extra arms, etc. Just as you can't put a VW pop-top on a Beetle (but you CAN on a VW van), there's no room for a whole bunch of turrets on a small mech. Heavy payload is like heavy-duty suspension, extra shocks, and that sort of thing. It's more about the internal structure of the mech than what can be attached to the infrastructure. So, basically, what I'm saying is, don't abuse the combination of these two effects... they're similar in game effect but intended to represent two totally separate effects!

Reese wrote:
do smaller steam power devices use up a minimum of one PU when thier size can be defined as small or tiny or diminutive, or do they only use up PU on a mech when they start becoming larger?
I'd treat this on a case-by-case basis, depending on what the items are. I don't count encumbrance when my PCs pick up silly little things... if the steam powers are reasonably small, I'd count it as 0. But if they started adding up, they should count. In short, ask your DM.

Reese wrote:
for instance, could i make a huge mech with an animators and discriminators combined using the integrated parts ability to run it (wihch would make the animator + discriminator combinations all tiny)and then use all 5 PU for weapons?
In this case, the animator + discriminator combination counts as a size value of 6. Per the table on page 54, that's Tiny. I'd say it counts as 0 PU. If you started adding this combo to every weapon on the mech, they'd count as 1 PU once they hit a size sum of 17 (which basically means you'd need 4 of them).
Reese wrote:
or, would i take the combined size of all steam powers used and determine the size (and, thus, PU usage) as a single entity?
(this one makes more sence to me, now that i think of it)
Yep, that's what I'd do (as above).