I don't see how Rail encourages first person shooter tactics, considering I've been using FPS tactics from the beginning of playing match mode back in Demo 2-3.
Aim still has a big factor in whether or not you hit the target with red rings, but it adds an additional factor, leading your shots. You shoot in front of the target, and by the time the ring gets there, it will hit him.
Another great FPS tactic that works great in SRB2 is getting yourself in a position where you're in a cramped area, and the other player cannot dodge your shot. For instance, thokking behind the couch in Zim's Base is a great tactic along these lines. Thok back there, turn around, and chuck a bunch of red rings. If they follow you, they always get hit.
Honestly, what Rail does is it allows you to peg people from across the map. This is a very important thing, especially in CTF, and the game would lose out on a lot if it was removed.
What needs to be removed, really, is homing. This isn't Mario Party, and rolling the dice should not determine the winner.