I actually think two of those issues are related - by releasing the 2nd FA to help serve coach, that FA is going between FC and coach often. And that means the curtain doesn't stay closed. However small the barrier to entry, that curtain is the difference between just a few people from coach going to the forward lav versus a constant stream.
I had the same experience yesterday - not only was there a constant stream of passengers from coach going to the forward lav, but the FAs even let the coach passengers stand between 3B/3E.
IMO I vastly prefer the order on UA flights where they have separate cordoned off areas for each boarding zone. I've booked flights onto UA just because I know what a ridiculous scrum some of the AA boarding areas will be. AA hasn't seem interested in solving this issue.