So while this is a total pain. By default the way to get up to a
basic user is:
They can get to trust level 1 by...
- entering at least 5 topics
- reading at least 30 posts
- spend a total of 10 minutes reading posts
At that point the restriction on private messages should vanish.
I think entering just means clicking on, not actually creating new ones.
Wish I could do more to help.