For pull ups, try find a jump box or plyo box. If you can't find one, then get a chair (something stable). Instead of using a machine for support, I suggest doing the pull ups until you gas, then put a foot in front of you on your support. That way you and the box or chair, whatever, become your spotter. You then hold yourself accountable to the amont of work you do, and you get forced reps. That method helped me quite a bit.
As far as building your yoke, I have never gotten results simply from shoulder or back exercises. Some people see results from deads, etc, but I have to work them out as a super set during another workout or give them time just for them. Shrugs are always a solid base, but have never quite been enough for me.
Take in mind this is my situation, not everyone elses'.
I also use a barbell clean, but I end it like a sumo high pull (elbows out bringing it up somewhere between my eyes and mid chest). I guess you could call it a plyo high pull. I find that lots of lower body explosion coupled with heavy weight is a good trap smasher. Instead of a dumbell row for lats, stand a little taller, lower the weight and do an explosive lawn mower pull super high with your elbow kicked out. Using those with barbell and dumbell shrugs, on db shrugs I like rep hold myself, with the occassional reverse peck deck I have been getting crazy results. It was noticeable in a matter of two weeks, if not in just days.
For a little extra fat burn that will strengthen your grip and traps try a farmers walk with the hex trap bar. Those are pretty fantastic, too.