The first, best mod is a 2.5" exhast system, turbo to rear bumper. Followed by an EGT probe in the exhaste manifold right below the turbo.
I'm running 25 PSI with no intercooler, my EGTs stay below 1300. Been running it this way for a few years and everthing is OK. Crushed a bearing in the tranny once, but other than that, no problem.
An intercooler is nice, I have intercoolers and intend to do that too, but its not a drop dead or do it thing.