I don't think your second question was addressed. If I read it correctly, you are asking about editing privileges for pre-1700 and pre-1500 profiles.
Since you are pre-1700 certified, you can edit open profiles back to 1500; but you would need pre-1500 certification to go back any further (or to assist in error correction for typos that have a pre-1500 date - seems to happen a lot!!).
Without pre-1500 certification, you would need to request help - or coordination, as you put it. But don't worry - we WikiTreers are always ready and willing to help each other when needed!