[tyland13]

Lootas have a place in alot of lists, and one of them definitly is mech. If youre going to face guard, SW and Eldar you need lootas for several different reasons:
1. For cracking open Chimeras, Rhinos and Falcons.
2. Cut down Assault Marines, Warp Spiders and anything fast to contest your objectives.
3. Try to out gun Heavy weapons teams, Pathfinders and Scouts with Sniper Rifles so that they don't pick off to many boyz.
So, I think that you should hack out some points to fit some lootas (but don't have them accompanied by meks!)

 

[tyland13]

Rokkit buggies are good anti tank, so yes that would work fine, but the lootas could be used to soften units on the pre-charge. You're right, if you don't get first turn they probably will get shot at, but if you do get first turn or they survive the shooting, they destroy.