I actually imagine FPS mode being better if it was TPS mode. The most confusing part about FPS mode is not being able to see my torso in relation to the rest of my body. I know there is a little indicator that shows you legs/torso alignment, but it's too hard to watch that and shoot stuff.
With a Third Person mode you would be able to see your leg/torso alignment better and keep your unit moving in the right direction.
A HUD similar to that used in MechWarrior (5 is coming out soon!) might work. Notice right below your firing reticle, there is a simple little bar that shows your angle of torso twist. It's right in your field of vision, no need to look down to see a weird little box picture. MW also had your torso return to center automatically if you weren't actually trying to aim at anything to the side (e.g. just running in a straight line without actively aiming at anything).
Fig. 1 I can has Razorback?
Last thing, I know everyone will jump on the "change your keybindings yourself" bandwagon, but I think the default "C" button to take control of a unit is problematic. Can't tell you how many times I try to hit Ctrl-C and end up accidentally entering FPS mode because the game was laggy or I missed the Ctrl button. It's especially bad if I have a long list of buildings or orders queued up for that unit, because it erases them. Sure, I can change the keybinding myself, but I'm sure I'm not the only person to encounter this problem, and with most games you want to encourage best "out of the box" behavior with fewer custom key bindings.