Regarding the difficulty latching and unlatching, as others have said, you are just not raising the trailer tongue/back of the truck high enough with the trailer jack. Raise it high enough that ALL of the tension is off the bars. At that point you can literally turn the latches with your bare hands, which is how I usually do it.
Every now and then I put a couple drops of oil in the joint there of the latches to keep them moving smoothly.
EDIT: also as another poster pointed out, make sure the bar is right under the latch when connecting or disconnecting. If the truck and trailer are not in a straight line, the bars will slightly off center.
EDIT 2: from the pictures, at least from what we can see from them, your set up looks good. You would need to verify by a trip to the scales to know for sure if you are restoring the correct weight to the steer axles. You said it drives/tows well, so it sounds like you are at least very close to right, and maybe exactly right on.
