Are you thinking of a map to go along with the mod pack, with bedrock walls already placed at 2000x2000?
Also, 5 to 10 hours? Damn. Who wants to play UHC for 10 hours straight? Can we add some mods to force combat?
Mindcrack does still do regular UHC's, so you have that going for you. Unfortunately, judging by the small amount that play on Crack The Beast as opposed to the vanilla Mindcrack server, not all of them have the time, interest, or familiarity with the mods to play FTB in any form.
1. No map, but we can use TiC to generate a Bedrock wall at a certain point.
2. I hope I'm not the only one.
3. They'll be other gamers out there anyway.