unclear word order

Das Bearbeiten von Feldern ist denjenigen erlaubt, die sie erstellt haben, sowie Kuratoren.

sounds good to me.

"Sowie" is smoother here indeed. This is, because it more likely implies a little Pause before it, than "und".

Whether or not a formulation with "dürfen" or "erlauben" is preferable, depends on style, and what other related messages use (which I do not know).

Thanks. Also I am happily learning from these discussions. :-)

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.