The following task creation policy is set:

• All users can create security tasks.
• Only members of Trusted Contributors may create non-security tasks.

(should also include the rHP -> /home/ stuff)

I would say the current create forms are fine, there should be 2 edit forms, 1 unrestricted one only visible to trusted users, and a restricted one that is only visible to non-trusted users (can be done with custom policy)

I’ll note that there is currently a restricted create form, for Trusted Contributors that allows anything to be changed.

I mean, that's not a particularly good solution to the problem. It just makes the time for which it appears to be fixed longer (even though nothing has changed)

I would suggest increasing the TTL to a day if you are not planning on moving servers in the near future.