unclear word order

Yes, your suggestion of "dürfen" spares a partizip and a nominalisation :-)

 Felder bearbeiten dürfen nur diejenigen, die sie erstellt haben, sowie Kuratoren.

And so shoooooort ! I added a the translation of "only". As far as i understood we found a good solution. So i make the change. Feel free to change if i am not right.