My bench press is low, and its a hard lift for me. I have a long heavy body and long lanky arms. What can I do besides bench to help me progress?
I have trouble squatting low enough due to knee pain and my lack of ankle mobility throes my form off and over stresses my back, can in just do weighted lunges and front squats?
Lastly, I cannot do a pull up. I am 6 foot seven inches and 268 pounds. I can do push ups pretty well though. What can I do to work up to doing a pull up?

Any other tips for a tall lanky lifter?