Couple things, first and foremost is safety. Although in my 50 odd years of working Snap Coupler equipment I have never had it happen it has been reported that the coupler can release under load. With the lift arms attached as you have them the plow cannot unlatch if the coupler releases and it will flip over on the operator, BAD DAY. Since you cannot easily convert that type plow to the proper lift latches that will release you have to take other steps to make it safe to pull. Two ways to fix it, that plow was originaly what is known as a pin hitch. Convert it back to a pin type draw point OR bolt a short length of chain to the plow drawbar and under the tractor is such a manner that it will retain the plow if it comes unlathed at the coupler. I go through the "H" link above the coupler when I do it. Make sure it is long enough to not bind when you lift the plow but not overly long.
Second thing is your hand clutch. Sounds like you have the proper rock trip that you should have for that type plow. It is designed to throw out the hand clutch when you hit a rock. As things wear they throw it out without due cause. Look just above the frame rail by your right foot is there "U" shaped divise that will push on the lever? If so you need to adjust it so you can plow without it pushing the clutch out.
Also from the pics it look slike you need to know about headlands and dead furrows. Wish I could show you instead of trying to explain it. Basicaly after ythe first time across the field you should turn a hard right and come back plowing right beside the first pass, not on top of it but right beside it leaving no unplowed dirt. Then when you get back where you started turn right again BUT drop the right tire down in the furrow formed during pass #1. Repate until the "land" gets wide enough to suit you. More from here but that will get you going in the right direction.