The most important thing is a good attitude. All the little stuff can be bought along the way. You've covered extra fuses. A few things on our must have list are: white lithium grease to lubricate outside, silicone spray to lubricate inside, extra cabinet latches and the screwdriver needed to replace them, duct tape, oil for the rig.
On the human side make sure you have prescription meds plus basic OTC meds including something for allergies even if you don't think you have them. Also a first aid kit is a must and pain med (Aleve, Advil, etc.)
Ear plugs are nice just in case. Bug stuff, sun block, anti-itch cream. Umbrella or rain gear. Charging cords. A good chair, a good book, and the ability to adapt, relax and enjoy. Don't sweat the small stuff. There are stores almost everywhere and you need less than you think Have an awesome trip!
Good attitude IS the most important thing to bring along. No question that PCs are well built and I've had remarkable success getting responses from the factory when I need it. Todays roads can be a bit rough and really shake the house. We've been on a circle Lake Michigan tour for the last 30 days. Toad braking system quit. (Not a PC part). Contacted MFG and had a replacement part in two days. Installed it myself. GCFI in bath tripped and wouldn't reset. Replaced it and still wouldn't reset. Bath, kitchen and outside receptacle are linked together and none worked. Called the factory and Doug called be back to trouble shoot. Thanks Doug! Outside receptacle had water in it from recent hard rain. Replaced receptacle and all is well. Yesterday some of the roads were so rough that a MGD shade fell off the wall. Hard to get to but a new screw fixed it. AHHH. The RV life! Things WILL happen just smile and move on.