Hi.
I really like this idea: merging at +3 seems like a nice balance between not letting code go into master unchecked and having all the reviews by few people only.
If some patch really got to be merged ASAP than I don't think it would be that hard to get extra +1 necessary: just ask at #osmocom :)
I think giving everybody ability to +2 patches and merge them right away defeats the very purpose of having code review system in a first place - we could just merge to master directly in this case.