I already know how to set up a remote turret. However when I made a ship turret (the huge ones that shoot beams) into a remote one it crashed the game when I tried to get into the chair. Whats the problem with this kind?

you have to set the pilotype of the heavy gun to "remote"

I did but I only noticed it was listed once unlike the other types of turrets so I think there might be one I'm missing. and if you don't change it it won't crash, it just won't let you get into the chair.