Best,

Robert

The technique used on heavy squats will be different than body weight or light weight. There is a lot going on in a squat or a deadlift and both are excellent exercises. You can certainly overdevelop a movement/muscular imbalance if they are done with poor form. You may feel an injury or you may not. Things that contribute to problems could be stuff like tight or overactive hamstrings, ankle restrictions, poor “core” control, quad dominance, upper back restriction etc. Obviously too complex to explain here.
Speaking of upper back, those exercises could be useful but a person really needs to first determine if the shoulders or the upper back itself needs the work. If so the upper back (thoracic spine) has to be adressed first and those exercises layered on top of that will only emphasize an already faulty software pattern. How do you determine which? I think that would be an excellent post. Stay tuned for that.

Best,
Robert

Sorry for the slow response. Last week I spilled coffee on my keyboard and the computer went down. I have had to use other computers while mine is being repaired.
You definitely do not have to start with pullups as your pulling exercise. I have found that doing incline pull ups for a period of time (something like working up to 3 sets of 30 at a low angle) will prepare you for pullups and chinups better than barreling straight in them. Blisters? Yeah well…you can try using chalk on your hands, but you will have to get through a period of developing calluses eventually. Lunges? You are probably better off without them (as you discovered). They are a fairly complex exercise to nail correctly. You are also correct that squats can easily be done wrong. I may have to shoot a squat progression and put it up in sequential episodes. There are several helpful supplemental exercises that can make a big difference in getting somebody in the squat groove. Please keep me posted on your progress!

Best,

Robert

Of course I know nothing of your background (how long exercising, exercise history, age, etc) but based on what you tell me the problem you will have is bigger than pushing/ pulling. It would be a whole body imbalance. Although you are off to a good start.
Really, to key in on it you can boil it down to a few moves and balance things out. Push ups are a great exercise. Running (depending on how you do it) can be a good cardio exercise. Next you may want to think about pulling exercises such as incline rows (see episode 13 workouts for vacations). Push ups and incline rows also address your abs, back, hips and legs in different ways. Then of course a leg exercise would be important, and too involved to just say do this cool exercise in a short post like this.
However…I would say your instinct is correct. Nothing but push ups can lead to an imbalance so I would say yes…..add a pulling exercise. Hope this helps?

Best,
Robert