A system like that would work for balancing. No doubt there.
The problem, as I see it, isn't that noone believes a fixed-class system wouldn't be balanced. It's easy to see that it would be. But I think what RazorAce and the other devs are trying to accomplish is to get the system working so that players aren't restricted to classes, but the overall system is balanced anyway. I think that they're trying to make it so that gunners can combine rockets, flamethrower, and lightning 3... yet the overall system is still balanced. I believe it can work.
Obviously, this kind of dynamic balancing is much harder to do...but I don't think they should give up on it just yet. It's actually pretty close, IMO.
1. Guns need to be tweaked to do more DP damage vs Jedi (so you don't have to spam shots).
2. Mishap needs to matter for gunners. I think mishap penalties should be added for all of the guns, with the amount of penalty depending on the gun. I'll go ahead and present some specific ideas for this based on my own thoughts and what has been discussed previously:
Running should double the mishap cost for using guns. Crouching should halve it. Firing from midair should increase it by 3x or maybe 4x.
The mishap bar would decrease at a fairly quick rate, so that it can go from full to 0 in 7-8 seconds. The regen rate would be halved if the player is running or midair.
If the mishap bar is too high (85% or so?) the gunner's accuracy suffers. Also, the gunner would be vulnerable to force powers even if they are usually protected, just like Jedi at high mishap.
Different guns would have different base mishap costs. Basically, the bigger the gun, the higher the mishap cost it incurs. Pistols would have a tiny mishap cost, while the rocket launcher and the flamethrower would have a huge mishap cost.
Does anyone else see where I'm trying to go with this?