No, MV fired four shots through several beta builds, when it was finally nerfed to three shots (and, having played several builds of full beta as a Trooper on my other account, my opinion was and is, it desperately needed the nerf from four shots to three because at 4 shots, it was ridiculously overpowered. Just my opinion, and I was at level 40-something when they nerfed it).
What they did not do was adjust the animation.
Having said that... MV and Full Auto are both as buggy as a Killik-infested underground Alderaanian fortress. They're broken and desperately need fixed because currently, our class is not a mirror version of Bounty Hunter (which I also play), we're like the Bounty Hunter's goofy little brother who does a bad job of trying to imitate him.
Stockstrike is just fine. There's nothing wrong with it at all. But MV and FA are decidedly broken and yes, there is more than half a second's delay on some Trooper skills that I do not see on my BH (when comparing the two side by side on activation times). In addition, Trooper skills get interrupted while BH skills do not - that's the fact of my experience. I'm not advocating a nerf of BH. I am saying fix Trooper and bring us inline with our Imperial counterparts, and do it sooner rather than later. Because Trooper is game-breakingly broken to the point that I have no desire to play mine.