did a quick test with kikaoh & tekken 2 they seem to work but u need to rename some to match the new cfg names (ex. for tekken2 ver b jap tk2b.cfg -> tekken2a.cfg). didn't test any others but u can create them quite easily either using latest mame or comparing cfg files for diffrences. all new games will have this needed in order to get the new characters, with old roms a rename of the cfg to the new correct cfg filename when needed should be enough.
I might do cfg's as well, but i don't like having to figure out which game has secret chars and how many. perhaps i should get an updated mameinfo.dat hehe.
about the trainer, i did a very quick check yesterday and got some of the older cheats to work again however i'm going to change the game detection first so that it can detect all the games, then i'll start converting cheats from the previous zinc(/trainer) and then start with cheats for the newer games (which i'll have to make from scratch). Before even releasing anything many testing will be done cause i don't like to release buggy soft! . All of this takes time, i'm working nowadays and time is an issue plus it's much work and don't wanna spend all my free time on it, i'll probably work on it on weekends or when i'm not partying or sumthing