What is the the best way other than larger exhaust to lower egts? How much will it lower with NOS? How much with Water/meth inj?

Where do you want to lower egts? At the track? Towing?

I am going to try my truck out at the local truck pulls this year. Am I going to have a problem?

Here is the general rule of thumb. If it ain't glowing / then it ain't going!! :) Just kidding! I wouldnt sweat it though with your mods no problem.

They likely won't allow NOS at the pulls. A bigger turbo charger is probably you best bet ;)

Im with those guys.

I hear people always say "stay away from the drugs" but what if any are the downsides to water/meth injection?

too much water, or a wrong mixture, ratio, whatever...and you're hydrolocked. Hydrolocking a cylinder is no fun, ask anyone who's been there.