The only real problems are the diffs and the steering bellcrank.

You will want to upgrade to the aluminum steering bellcrank and upgrade to Gene's crosspins. Other than that, get a general set-up from the Cen Racing website http://www.cenracing.com/race/setup.html and fine tune the buggy's set-up to suite your driving style.
The CEN FRE/Pro is a great durable buggy. Hope this helps.