Admin Rights for Players

It seems, in order to play Roll20 I need to give local admin rights to the players for their character sheets. I have just removed a player from my group for upping his XP when he thought I wasnt looking.  I am not always looking - so PLEASE is there a way in which players can be  1) stopped from having local admin right to their sheet but still play with it sensibly (HPs, Temp HP, adding items , amending spell usage etc)  2) protected from "mistakes" by creating a log of all changes to the sheets so that I can parse the log and call out mistakes. 

This would have to be done on field-by-field basis. If you want to prevent players giving themselves extra XP, perhaps other GMs will want to prevent players giving themselves a vorpal sword (or other items of equipment).

I agree , but feel that if 1) is onerous, surely  2) is an acceptable and easy to implement compromise? 

The option would be great, but it would have to come as a plugin for the sheet creators. So basically you wouldn't see a difference until the sheet creators update each of their sheets. Even then each GM would probably want slightly different settings so while I'll support the idea I doubt it's going to be an easy feature.