Welcome to the forum!
This is my exact setup that has worked great for over a year.
I would like a Pi 4 with more ram (not that my OH setup needs it) but with current issues I’m gonna wait till a later version rolls out and hope the bugs are worked out.
SSD will eventually fail but is much better IMHO than SD card. Either route you pick just make sure you make a backup and verify it works. Nothing ruins a good day like losing all your hard work and no way to restore it. If you do decide to go the SD card route check out this topic ZRAM status as it may help with sd wearing out.
Can’t help with this one, I use zigbee with zigbee2mqtt and a CC2531 coordinator with no issues. You may want to check your location to make sure whatever zwave stick works.