When linking turns, are you supposed to unweighted both feet, or just the front foot? For ex. Your in a toe side traverse, to do a heels side turn, do I keep the grip on my back toes, while transferring weight to my front heel to initiate a heel side turn? And if so, how soon after putting weight on my front heel do I put pressure on my back heel in a turn?
Same thing toe side.
Also, should weight always be on the front foot, and knees always be bent?
People say to stay low, but when watching other riders, they don't seem to always have their knees bent.
Assuming you're talking about isolated beginner turns, you don't necessarily "unweight" the feet. You want to make sure both knee's are bent, and I try to teach my students to have their weight pointed downhill. The point of that is to encourage the student to make sure their weight is on their lead foot to try and avoid encouraging rudder steering. After that, you start the rotation with the shoulders, and follow through with the hips, knees and ankles to get the board around. If you do this correctly, you should essentially be able to make the turn around someone standing stationary.