If you just put together some changes and make pull requests for them on github (help.github.com is a great resource if you don’t know how, also there are some step-by-step guides on the forums), people will offer feedback. I’m not trying to discourage anyone from accepting your request, just pointing out an alternative, it’s kind of a crowdsourced mentorship dealy.
There are a few people that might be rude, but the vast majority are happy to help.
Also if you drop in on irc.freendode.org in #CataclysmDDA a number of the devs hang out there and will usually be happy to help you out.