This is pretty much word for work of my own male bun xD
I would definitely suggest getting at least one of them fixed (panda would probably be a better choice, but I would suggest both if possible) and then bond them so you do not have to worry. I still haven’t completely bonded my two so my Quicksilver still harasses his big sister lol
For peeing on the bed, all I can really suggest is keeping him off the bed. If you can’t be home, put something around the bed so he can’t get on it or something on the bed so he doesn’t want to be up there. Fixing him might help with this, as it helped with my bun.
Baby gates, yea, learned the hard way those don’t work lol. I actually use a plastic gating or lining or whatever you want to call it. Kinda looks like chicken wire or gating, is plastic, can be found in the outdoor section of the hardware store with the gates and they usually sell it at different heights. The kind I get is a dark green. Pretty tough plastic but you may have to replace it or flip it now and then until your bun realizes chewing it won’t get him far. Only thing I’ve found that can be hung without a huge fight lol