Wow, since I stopped using Mame at around v37 or so (changed PC, too lazy and too busy to reinstall....etc), this scene has grown by an amazing amount....and so has my collection of games now that I seem to be attracted back to the hobby. This is probably not the ideal place to ask, since we're more concerned with controls and tinkering with hardware, but I have looked around elsewhere with no luck. So I figure if you got this far in your projects, you can send me off in the right direction to figure out the software side

Now I'm overwhelmed by differing versions of MAME and too many roms to manage, especially since I'm branching out of Mame32. I've tried a search here and a few other places, and snagged both clrmame and romcenter, but I could really use some simplified help on rom management, if anyone could point me in the right direction, I'll get busy reading. If this is not the place to ask such questions, or the answers can be found elsewhere, just ignore the following and let me know where to look.
I have already noticed that some roms only work in a certain version of Mame (dos, M32, winmame), and I have managed to make rom center do what I think I want, but I am still confused:
Red icons mean death apparently (in RomCenter). Does this mean I just ditch the file? No hope of ever using it again? How about saving it for a later version? I ask because I have initially made filesets for each version of Mame I am using, and narrowing down each set to a 'working' file archive. This obviously gets confusing fast when different versions of Mame produce different 'good' results from the same initial set of zip files.
WTF are datfiles? OK, I get the basic idea, but in RC I managed to have it find the mame data and create a datfile. Why use an external datfile that can be downloaded? I gather there must be some benefit to doing so, but I have yet to see it.