We've had gizmos and gadgets gillore over the years. And the truth-be-told, we have found "simplicity" is still the best. Leveling? a simple small carpenter's level, a few block of wood under your jacks for leveling and support. Garden hose, sewer hose, electric extension cord to connect to shore power.
After that, pretty much everything else is just "fluff" and "stuff".... toys that get dragged along to help inflate an ego and feel important. (I know, I've been there and done that).
I have a Surge Protector. I see the value in having that.
After these items, the only absolute "must have" ... that I will not leave at home without when camping, is the good old fashioned hand held ... potato peeler! I love my potatoes!
Level Left to right using the door frame. It's always straight to the trailer, and then forward and back on the frame also. You'll never go wrong with this.

