Not sure where I stand on the hitboxes. I feel like your idea from back when (where a drone with shields has a sphere hitbox, and a drone with no shields has just their mesh as the hitbox) should be given a shot in a playtest.....but getting back to it....
The game in the video, "Starsiege", had a similar gameplay issue to what we have now. Lots and lots of non-hitscan projectile weapons, and lots of squirmy moving targets (not well shown in the video, but good light-medium pilots in multiplayer were very tough to hit consistently).
I personally played a fair deal of this and if it weren't for that indicator, I wouldn't hit much. I know because if you run out of power for your vehicle(you can shoot your reactor dry), your hud shuts down along with the lead indicator. It's tough to hit anything outside of point blank in that state. Also, a possible positive side effect would be that energy doesn't run out as fast as you won't take shots that your lead indicator shows to be way off the mark)
The wide-cannon placement is surely an issue. In that game, the projectiles would converge on your point of aim. We dont have that.
Also, Starsiege is free to play and download from HiRez Studios
Worth a try. It's a great game in it's own right. Or, at least you to get to try that lead indicator