In most instances, one screw-up does not cost you the match; if you're SDing and losing then that's entirely your fault.
If the match doesn't last long enough for you, then either you're dominating your opponent (which would be showing your skill) or you're getting dominated, I don't really get the problem here. Playing more matches would easily remedy this unsatisfied feeling.
The setting doesn't force players to play differently; the players are the ones forcing themselves to change. I play exactly how I play in friend 1-on-1s, and I've not had a problem. I've come back to win many times after being the first to lose a stock, so that's not really a problem either.
That said, I too I prefer playing with three stocks but I'm perfectly fine playing with two instead.
I do agree Final Destination is not the best choice of stage for For Glory (Battlefield would be far more balanced in my opinion) as it gives certain characters advantages, but I've never had trouble dealing with Little Mac users, especially considering Final Destination is not a walk-off and he must jump if he wishes to recover once he's knocked off the stage.
And finally, I've found five minutes (with two stocks) to be very ample time to defeat my opponents, and I've yet to have a match I'm in run out of time, or even surpass three minutes. Besides, this complaint is in direct contradiction with what you just said about matches being too fast-paced.