In my understanding of your problem, you're just experiencing a move of the metal on the horizontal plane, not the vertical plane. Since the load on the hitch should be on the vertical plane (by and large) any stressing and loss of capacity on the vertical plane via the adjustment on the horizontal plane should be minimal. There might be some discussion as to whether or not you bent the frame of the hitch at the base of the legs that run front-to-rear of the vehicle or if you bent them at some mid-point. I would say this to you, whatever stresses you have applied to the material are along the horizontal plane where load is less applied by the towed unit than if it was vertical plane. Furthermore, these things are manufactured with a certain tolerance; e.g. if the hitch is capable of handling 500 Lbs. tongue weight it won't FAIL at 500 pounds, it might fail at 700 or 800 pounds; 500 is just the "rated capacity"; i.e. what it can handle safely. So, 1) you have some room on the numbers to play with and 2) we're talking failure at maximums; if the hitch you installed is a Class III or whatever that might only be rated for 300 pounds tongue weight (rated, not *failure weight* and all you ever do is haul around a law mower trailer that tops out at 180 pounds tongue weight then, you're fine.
Ultimately you have to do what you feel best with. Even as picky as I am, I'd not sweat it.
Seriously, I sweat the details (and it works well for me), but this sounds like you're being obsessively obsessive. :) It'll be fine You think not, take a trip to some rural areas and see what the yahoo's are using to tow stuff. :)