Here's my list of things to do/check before our first trip in April. What would you add? What am I missing?
Seem to be missing any slide checks: Make sure slide operates without issues.
Check LP system and make sure all appliances are in working order...including the electrical side of everything (A/C's, fridge, blower motors, water heater). Fill fresh tank after cleaning. Pressurize water system and check for leaks. Check seals in toilets. Re-tighten all cabinet hinges.
Good list, also try to check for any loose wires under the RV and zip any that are suspect. Make sure you have your insurance card and road side assist #'s inside the RV.
Maybe Check and tighten all the wiring/connections in and around your fuse panel (the big inside panel with AC and DC) and check for anything else that is loose thoughout the RV. I had to tighen several connections in my fuse box.
When greasing the front end, your drive shaft at transmission output and u-joints most likely have fittings also. Check your wipers and fluid. Make sure your refrigerator is working. You have a great start on your list. It may not seem like it outside, but spring is coming.
I didnt find any zerk fitting on my ujoints (E450 Axis) but I did check to make sure they were tight .....along with the center drive shaft carrier.
Normally you can get like 75K+ miles out of ujoints (in my experience) and they are easy (and cheap) to replace. So unless your driving off road a lot or heavy loads/towing you should be fine until 75 K miles IMO (but check at least once a year).
On my jeep I started replacing them every 40K miles (or so) to be safe but I make sure I have zerk fittings on new joints and lubed them twice a year.
Jacked up Jeeps that get used off road some go though U joints much quicker.
The ice cubes are ineffective. The Tornado tank sprayer is much better.
The ice does work. I used that on previous TT several times and it worked. In the video above, the guy mixed up his simulation and plastered it to the inside of a totally dry tank...then set it out in the sun on black cloth to super dry for over an hour. If he had put a small amount of water in the tank (as our black tanks usually have in them) prior to adding his mixture and immediately drove around...the results would have been much different. The ice did remove a fair amount of material anyway...just not his stucco/sheet rock mud job he made. The bottom of our black tanks are never totally dry and baking in the open sun.
Clean and lubricate all outside hinges and latches.
Fresh batteries in all remotes, smoke detector, other devices.
Check and clean refrigerator vent, furnace vent.
Don't forget to treat all slide seals, inside and out, check to make sure no screws are protruding from the seal edge/holder as well.