That would be perfect for especially me
But for like lv 1-3 admins, who abuse (ie. ExZii) how can regular users report them? Spec'ing them if the only real way of reporting and capturing enough evidence. It doesn't happen all the time, so i guess wouldn't need to be thought about to much.
Anyway Great Suggestion! 
You have to out weigh the good and the bad from Regular players spectating.
And The bad from regular players spectating Is worse than the good it has.
If there is a hacker and regular players want to report them.
I have another suggestion.
Make an offline report system so when you join you can do a cmd like /oreports and it will open a box with all the reports that players made while an admin is not online.