I say we petition to have theoretical physicists gain an interest in Fallout and the community. Then we can bug them anytime we have a question on the forums.
I learned quite a bit about basic physics, not enough to be theoretical physicist, but enough to know how things work on basic level.
Plasma is indeed superheated gas, so it cannot be stored in containers made of physical materials - it has to be held by magnetic fields. I belive those "plasma containers" in Fallout games are just full of material that can be very easily turned into actual plasma. It's turned as it leaves the gun and most likely magnetic force pushes formed plasma projectile forward.
Also there is one significiant thing distinguishing plasma in FNV from real life equivalent - getting hit by plasma should have additional effect - electromagnetic pulse. It doesn't in NV.
I just hope the Brootherhood scribes make a weapon which combines Laser and Plasma weapons like a green laser rifle powerfull, acurate and quick I always hear the scribes talking about it and I never find one in any Fallout game - Annoying. I have no idea about your actual question
There is a weapon in OWB that combines laser, plasma and electricity. It's LAER (Laser-Assisted Electrical Rifle).
The laser used by it is so hot, that it turns air it goes through into ionised gas - plasma. Plasma is a conductor for electicity - such plasma beam lasts for a blink of an eye, but it's enough to create a link between LAER and its target to put electric current though it.
I hope it's understandable; I was studying physics in different language.