It's almost impossible to suggest a pitch curve for your heli. Every heli is different. The pitch curve and throttle curve have to be set to compliment each other. I try to maintain a steady RPM throughout pitch curve. If you not running a governor it will never be perfect, but you can get it close with enough tinkering. Setting the pitch will depend on the RPM desired, weight of the heli and power available.It's really a trial and error procedure. If you have any heli pilots close, you might want to look them up and walk you through the set-up procedures. It does require a bit of explaining.

I do try to have the collective/throttle stick a little above half way at hover. You didn't say what stage of flying you are at, so it's also hard to give instructions not knowing your abilities, or even what type of flying you intend to do.

Since you are using a .37 engine in a 50 size scale fuse, you're not going to have a lot of engine to spare.

Another thought...Have you checked the balance of the Main blades, tail blades and the flybar? Another vibe problem can come from a bent tail rotor shaft. They may run at 8000 RPM and even a small bend can produce a significant vibe.