I swear you've watched all of ESB frame by frame, haven't you ImpFighter? ;)

Re: Luke's ripped shoulder, I think the rip is evident in all the shots you posted. In the shots just before his hand gets chopped off (where he's lying on his back), you can see a lot of material bunched up. I think the rip's still there, but the material's all scrunched up because of the way he's lying.

Similarly, in the shots of Luke hanging on to the end of the vane, you can still see a split in the material. Although not clear in the shot where Luke's kneeling (because of the post being in front of him), in the subsequent shots you can clearly see a rip between the shoulder and sleeve of his jacket. I think the reason it's not more evident is because his arm is raised (hence allowing the material to drop back into place).

Edit: updated post with clearer screencaps.