A few thoughts.
First thing when unhitching. Chocks in
Last thing when hitching. Chocks out.
I only put the jacks down electrically a couple of inches before pulling the pins and dropping them manually. But if I am parked on an uphill, I know I will have to lower them farther so I can level the trailer after unhooking.
If you are having trouble pulling the unlock lever, put the truck in neutral and release the brake to remove any pressure the truck may be putting on the hitch. Re apply the brake and pull the handle.
I just use a single piece of 2X6 under my landing gear feet. I have seen rigs blown off tall blocks in high winds and their gear damaged. The possibility of being shaken off the blocks is also a consideration if you are in quake prone areas.