If it's just a very small amount of play, and you've got the rotor screw on there tight, I wouldn't worry about it. Mine has a small amount of play as well and it's fairly new.

The ignition rotor is cheap and easy to replace so might as well try a new one, but unless there's a lot of corrosion/build-up on it, I don't think a new one is going to fix your problems.

I'd try the easy and cheap things first, like fuel-injector cleaner, look over the plug wires for cracks, a new cap along w/ the rotor.

Were you getting low pressure with a gauge before you changed the regulator? A badly clogged fuel filter could be the cause of low pressure, if that's the case.