Oh I see, you have a good point. I am not an artist either, but I do understand the huge amount of time it takes. I have respect for artists like you.
Well the cash system is actually available in RA v1.10 already, just need to implement an adoptable shop or itemshop. I have some of the features you suggested on my own adoptable site(itemshop, happiness for instance), the breeding system will be completed soon, and food/hunger is planned. You may take a look at it if interested:
http://www.pokemansion.net/
For now I will try to make a publicly usable itemshop, since mine is heavily customized for my own site. Breeding by species is actually not that difficult, all you have to do is to add one or two lines in Arianna's simple breeding system.