Were the visitors even physical? Benevolent Solaris?

The points made for the visitors being physical are that our human characters are able to touch them. I am unsure of what to think, here are my thoughts.

I'm inclined to believe that Solaris is one huge sentient organism and probably has some kind of psychic abilities which it would employ against the annoying aliens orbiting it in a spacecraft.

Could the visitors be an illusion created by Solaris after reading the minds of the humans. The brains of the humans could have be stimulated into believing that they were capable of touching the visitors.

However, why were the humans able to see each others' visitors, is it a shared delusion?

If the visitors were not physical, what was the point of having Rheya kill herself and resurrect, also, the other crew members have seen resurrections before too.

And, what was the point of having visitor-snow around?

If visitor-snow was not physical, he would not have been able to chuck real snow in the ceiling.

Or, real snow is mentally weak and made to believe that he was visitor-snow, and the dead snow is the visitor-snow.

Regardless, Solaris' intention was probably to get the humans to leave.
Perhaps Solaris was compassionate in some way, choosing to somehow convince the humans to leave.
It succeeded in getting Gordon to leave.
As for Clooney, Solaris might have chosen to give him one last good dream before he plummeted to death in the space station.

In this case, if the Snow left on the station with Clooney was a visitor, he probably stopped functioning (?) as his purpose was done. Maybe he even felt bliss at returning to his creator if he was capable of thought. That's one way to explain his "O" face at the end.

If the Snow left on the station with Clooney was the real Snow, which I think is improbable by now, he could have been subjected to some happy last dream like Clooney, which also explains the "O" face.

Wish we got to see if Gordon made it back to Earth, would she be treated as a Crackpot or survivor of a perilous first encounter...