I believe that for most of the people that gravitate towards the DCC RPG, one of the appeals of the game is that it is fairly simple and straightforward (freeing up the Judge and players to get on with gaming), and that in posing this question, quite a few responses to this topic could easily be assumed to be "I wouldn't change a thing, I love it exactly as it is."
Being fully aware of that consideration, I thought I would still ask: If you were going to create an "Advanced" version of the Dungeon Crawl Classics RPG, what would you add to the game?
I've been thinking on it a bit, but haven't come up with a comprehensive personal list as of yet, so I wanted to see what ideas other people might have. One caveat that I know I would want to keep is compatibility with the existing DCC game and modules, but that is about as far as I have gotten.
One thing the players in my gaming group have mentioned would be splitting race from class in following the tradition of AD&D. Another would be the addition of some races (Gnome) and classes.
Scrapping race as class is not a complicated task but it is a major overhaul of the flavour of the game and it robs humans of their 'special ability' that of being able to choose their class rather than being stuck with what they get which is their compensation for the special abilities of the demi-humans.
There are certainly tweaks that can and possibly ought to be added to the demi-human classes (Why can an Elf, a tree dwelling creature, not climb better than the average human for example?) and I expect the odd additional non-human could be considered, Gnomes, Halfies or whatever.
I have a small selection of general & adventure skills: riding, swimming, boating, climbing etc. which evreyone gets a D10 to attempt but which some get D10+2 or D20 or D20 (+1/level after 1st). Some backgrounds bump up certain skills, some classes bump them up further and there is a bit of player choice too. That helps achieve some of what you are after and their are a couple of tweak packages such as the Holy Warrior (Drop hit die, reduction in special combat skills, more limited weapon list etc in exchange lay hands and/or turn unholy), Elves can sacrifice a spell for an additional skill and so on.