Can i remove these?

What are these bolts for?

(Tried to upload photo and failed)
There are several bolts on the inside of the space frame with rubber washer/grommets.

Can i remove them to use them to mount things?

yes, the rubber is an expansion nut, kinda like a riv nut, remove the bolt from it, and bolt whatever is needed to it.

that’s EXACTLY what they are meant for. I swapped mine out for hooks the first day. just be careful not to tighten them too much or the rubber will rip… replacements are available at a good hardware store…