F Bulkhead row is my usual choice, and in many years of flying on AS I've only encountered this problem twice. Once (1st pax on board) when I opened the closed bin and found it full of crew bags the F/A immediately stepped over and moved them. The other time in the exact same scenario, the F/A saw me open the bin and told me I'd need to store mine further back. I pulled my phone out and started to take a picture of the bin (complete with it's sign indicating these bins are reserved for front row pax), and lo and behold the F/A lunged for the bin and moved her stuff. Problem solved, but not a chronic problem among the usually excellent AS crews.
In terms of protecting F bin space for late arriving F pax, there is a lot less consistency. Whenever I see an F/A actively doing that, I go out of my way to thank them for the consideration.