I haven't had a trailer for a few years, but in general, I'll assume its a 23' trailer, and that ac should be fine, 1 slide?
Silicone caulk is a no no, you will want a urethane based caulk like Dicor.
Battery and or generator for off grid, how much time will you do that, but a battery will keep the fridge running while driving along with a charge line from your tow vehicle
Ok its a 26' trailer @ a little over 4k# make sure you have enough tow vehicle, I would stay under 75% of my tow rating
When you do get it, do your 1st trip close to home or in the driveway to get used to things
Mike & Becky
2005 Crescendo 8356