first you should do a lot of research here....
http://en.wikipedia.org/wiki/Insomnia.
LOL. if you dont have it all ready just give it time. im fairly new and lets say all i do is play with the damn thing and look up stuff to do with to it while im at work.
i never thought about flashing a phone nor knew what it was until a couple weeks ago then i finally did it last week and lets say now i am glad i decided no to chuck it off the searis tower. now i dont know how many of those roms Doc ee listed above are for the fuze. i believe(dont quote me) that a lot of those are cdma roms only. i cant really give u examples for your phone bc i too have a cdma version.
as for apps i personally get most of them from
www.freewarepocketpc.net . not a shabby place. also the links in darkness's post are really really helpful. have fun