When you install a new version it won't ask for your code again as long as you just close PT3 and install over the top.
Please read the
Tournaments FAQ for your SNG issue.
What version of PT3 are you using? There shouldn't be any inactive controls in the latest versions (e.g. Beta 30.3 onwards). If so, please let us know exactly what you can't access.
What is your ticket number?