1. as said this was a research-project trying to bend behaviour to my needs, fencing gave alot of issues, so i turned it off, and never looked back to be honest.
2. i never had a full cluster/network fallout, so i have not reproduced this behaviour.
3. not have had that issue.
4. i am atm running latest pve-kernel-5.4/stable 6.2-6
My setup atm = 4x DL360Gen7 + MSA2040SAS+ 1 shelf added
Tell me, please, what about you network configuration? Have you link aggregation? What's the switch? Cisco? Microtik?