DC is not using the traits file.
And some of what is in their is hard-coded, some is not implemented at this time, nor will it be until after 1.0
As for races, I've successfully used 8 in a design. I think Steve McDonald go the number a little higher. I don't know off the top of my head, but I think that there might be a max number that DC will read, but I don't know why it was set up this way. It shouldn't be too hard to change at some future date. But, as it is, I think we could have upwards of 48 races if we didn't mind them being different only in name.
Classes are a bit trickier. They are hard-coded into DC, so we can change the name but not the function and anything we add after the original group will have weird level issues, in that some of them may not have any levels at all. This is not good for PCs but it is fine for NPCs, as we can manually set HP, stats and THAC0.
After the inner band of the city is filled, the rules will change. Then, the rulle will be if it is your first ward, you must be in the second ring, but if it's your second or subsequent ward, you must be connected to at least one other ward, but it will need to be in an available ward of which the map will show. At first this last part won't matter, but if everybody wants to build south, I will need to reshape the city as city's generally grow in a ring fashion unless there is some barrier to stop them from moving in a direction.
I'll update the map, Dinonykos, as soon as I get home in a couple of days and then hopefully update the site the same day.