Plasma cannons need a larger splash radius and a 50% overall damage boost. in this video I explain(very poorly) the high and almost unattainable skill cap you need to chuck plasma. Check it out.
Where were you the entirety of Alpha. Two for one on this video. It covers both plasma cheese and poor spawning mechanics.
The issue here isnt that plasma is too good, but that spawns arent varied and are exploitable like this. Everything else about plasma is no more broken than the auto cannon or the power fist.
Meh...its not just Plasma that can do this. I have fond memories of swinging my PF on my MoN on Harkus walls and getting 5-8 kills with one swing because I happened to swing at the spawn spot back in Alpha.
Yeah its a shame the Stalker Bolter is currently obsolete. Granted even when it was good it was too easy to hipshot/no scope(literally) in close quarters.