Very nice djlunchbox! Stick with what works. And MA does work! New ROMS, new systems, updated this, updated that...... whatever. Having a bazzilion classic games and platforms is what makes your cabinet. And if it ain't broke.... lol.
As you're finding, if you can run an emulator on your system, it'll most likely work through MA. Some are just a matter of which "Available" emulator do you chose to redirect. For example mine has Coleco Colecovision redirected to Pinball FX2.
For MAME I use 0197 and a ROM set 0193. (please don't ask why...lol). My ROM set originally had 16.7k 'games'. Of course not all working and a lot of hacks/remakes/dupes. I don't remember my exact method of weeding through them, but it consisted of of filtering out 'available' -and- 'working' games. Exporting/saving an XML filtered list. I think I ended using Rom Lister (in fact, I think this was my main tool). I did the filtering and I either saved it as a MA .lst file..... OR .... saved as a .txt file and used Maximus GameList Converter to convert it to .lst. Again, I tried several different ways/methinds and this was quite a while ago. My next step was a little more daunting. Mainly because of my ignorance, I'm sure. Manually went through and deleted consoles such as Commodore and TI. Also took out Mahjong and bar-top poker games (personal preference). My current working set is down to about 3700 barring some more 'personal preference' filtering.
I know there's probably an easier way and lots of "I would-a", "I could-a", "I should-a" and "if only I had-a". But hey, this is how we (or at least, I) learn.
Keep it up. Keep it alive. Keep us posted.