i have some questions / problems with certain exercises and would be glad if you could help

box squats: are you supposed to effectively sit down, rest a mili-second and then push back up (which is much harder) or is it enough to just "tip" the box without "resting" and then go back up (which is much easier)?

sumo deads: how wide is your stance supposed to be? mine is usualy very wide, my feet and knees point into the same direction, but at a very wide angle nearly parallel to the bar... - maybe any good instruction video?

the real problem comes while pulling - when i pull the weight back and up, my knees are always in the way of the bar and i need to pull the bar "over" my knees - to do so, i have to lean more forward = more strain on lower back and less power... is that a flaw in my technique or just the way it is? any way to correct it? i know you dont have that problem with a trap bar, but i dont have access to one...

rear delt: there are plenty of possible rear delt / upper back exercises to choose from such as rear delt flys (db, cable or machine), face pulls, scarecrows or seated db powercleans - i have tried them all but am still not sure if they do and which appeals the most to me... i kind of like powercleans cause you can do am dynamically but dont want to risk any rotator cuff problems

rack lockouts / floor press: any difference between rack lockouts to upper arms parallel to floor and floor presses?

which rear delt exercises would you recommend me or where do you see the pros and cons of each?



thank you all!