Although I wonder if the ones that dive deep in would pull streams of gas or something like the one I found?
I don't know anything about that type of stellar interaction, but I do know that a companion star, if close enough, can actually pull gas off the other. I know white dwarf stars do that. In any case, SE doesn't simulate gravitational outside of initial system generation and while piloting starships.
But they are completely opaque, so it seems they have a solid surface
In SE yes, but not in reality, especially for the very big ones.
Also Major, you posted this in the completely wrong section of the forum. Additionally, there are existing threads where your post could have fit. Please try to be mindful of the forum rules when posting.