Before more serious work, begin by replacing the window motor pucks, which are the weakest link(built in) and usually what fail first with a window issue. Also verify that the window is adjusted properly, it should not move around side to side at any point. Roll it half way down, and by hand try to move the back part up and the front part down, plus the opposite. The glass should not move much at all doing that, if it does, it needs to have the window guide adjusted. That's inside the door at the back, the long(20") glass guide, with a single bolt holding it at the bottom(gold head bolt at the bottom corner of the door). Loosen that bolt and move it forward until it has slight resistance, that makes the guide hold tighter on the glass at the back edge.
Those two things will help a lot. Also if there is any corrosion inside the glass channel(all around the top etc(it is one part), then rust will be squeezing on the glass, making it too tight at the front edge(the channel it slide inside of ).