Do you believe there can be an Actual Infinite
“But if one removed all phyiscal mass and energy, both the visible and dark, wouldn't empty space simply be infinite vacuum?”
Dark energy maybe inherent to space so it’s not possible to remove it.
“Would you then believe that if space is finite, expansion of the universe will hit the "edges" of space one day? Or do you believe that the expansion of the physical universe determines the size of the space it's in, which is finite?”
We live in 4D space time. I’m not sure but maybe as you get closer and closer to the edge of the universe, time slows down and then reaches a stop? So you can never pass the boundaries as time does not exist outside.
‘If time reached back infinitely, it would reach the future infinitely as well?’
Time does not reach back infinity far that would be an actual infinity. Is time future infinite, that is only a potential infinity in a 3D + Time world but it is an actual infinity if you buy Einstein. I buy Einstein so time has an end too for me.