Are there any back exercises (preferably compound) which minimize the contribution of the biceps, so one can work their back without stressing the elbow joint?
Use the search function. You ask so many questions and they can all be answered by 1) actually lifting weights and 2) using the search function. There are hundreds and hundreds of posts on here about back exercises. You’re holding back any progress by overthinking everything. Lifting weights isn’t anywhere near as complicated as you make it. Stop thinking so much and actually go to the gym and experiment. Fail and learn from your mistakes. Don’t be lazy and expect people to keep spoon-feeding you.
I personally find that DB rows, really hammer my lats and middle back, and don’t affect my biceps all that much. Mainly high rep, Kroc rows.
Not sure why. Good stretch at the bottom, then pull to my lower ribs, just hammers my back and I wouldn’t notice my arms. They are just meat hooks at that point.
I’ve been doing barbell rows and dumbbell rows, can’t do pull-ups/downs.
pendlay row. chinese DB row. meadows row. db/machine pullover. kayak row. stretchers. below-knee/knee deadlift (w/ chains if you want).
You could try using a pair of ab straps, like people use for hanging leg raises. Put them down by your elbows for lat pulldowns and cable rows. This may help at some of your pulling volume be less demanding on the biceps. You will probably still need to grab a hold of something with your hands, but try to concentrate on pulling your elbows/scapula down/back.