I'd rather just do my four sets of squats with rests in between, then four sets of deadlifts, then come back from squatting and find that the weight I was deadlifting is in use.
Then do that
For RDL, just DL the weight up, then unlock your knees a bit, bend at the hips keeping the lower back in a decent arch until you feel some stretch in the hamstrings, then pull back with the hamstrings and squeeze the glutes.
If you want something that will tell you what weight to do, you can look into "5/3/1," otherwise just add weight when you get all your sets and reps with good form.
Somebody else should be able to answer your question about your elbow better than I can.