How do you know you're towing too much weight?

Also it took a lot of practice to keep the 200 hp. motor rpm under 3000 rpm.

I think this is where most people get uncomfortable. The problem is there is no reason for it. Naturally aspirated engines make most of their power in the higher rpm range (ie above 3000). Don't be afraid to let them rev, it won't hurt it. Sure it can be a little noisy and annoying but it's not going to blow up.