Sorry to hear about your loss. Bloat in Labs is not that common.
I do not feed senior feed, just all life stages. Typically less food as their needs decrease, but I often add frozen green beans so they don't feel like they are starving. I have not fed joint supplements to my dogs, just a good diet, and try to keep them lean. Some people swear by them or use them for mild pain relief. I'm sure they'll join in with advice.
As far as beds, I do get the dogs really thick beds when they get old, so they don't get cold from the floor or feel the floor (I have all tile and hardwood). But, if they are too thick (crib mattress, for example) the really old dogs can have trouble getting off and on.