What's up guys? [8D]

I've got an RC18T that hasn't been driven in a looong time. So I've decided to rebuild it some what and I need some advice. First, I'll state the set-up I'm going to run and we'll go from there.

It's an RC18T (kit version) and I've got some MIP diffs and steel gears on the way, it's running a Mamba 8,000 Kv motor and matching ESC. I'll be running it on a 3S 1550 lipo, which brings up the first question. What's the best gearing for all-around bashing/racing? I still want some wheelies, but also want to run high speeds (50 mph+).

Next is steering. I've got a new DP draglink coming, I remember the first one I had helped, but not as much as I wanted it to. So what other things can be done to fix/tighten up the steering?

And finally, the differential set-up. How tight do you guys run them? I had a steel one in the back with a one-way spool up front, but didn't really like it, which is why I decided to order two diffs. Should I just go ahead and lock them both up, or run them ever so slightly loose??

Thanks for any and all advice.