A digital air pressure gauge. Road Gear makes a good one. Several types for different applications. One for the bike, one for the house/garage, etc. Don't know how to post a link but you can find them on any search engine. Cost about 30 bucks and up.
Actually got on my buddy's RK yesterday for a bit in the parking lot. It is amazing how fast it comes back. Trying not to overthink everything. Once I got used to where the controls were and how they caught etc, I was pretty comfortable.
That was in the parking lot. Traffic has always been of concern to me and I learned to ride by leaving yourself an out. I do that whether I am in a cage or on 2 wheels.
Significant parking lot time, except to get gas, is anticipated.
Insurance - check
Rain gear - check
Service manual - great idea, will order one
Pledge - streak free already in the garage for the cage
Install your engine guard, it will save your pride when least expected, it saved mine twice after a long ride then going and moving around parking lot at slower speed (stay away from front brake) ;0)
MSF beginning rider course. Enjoy that beautiful Heritage and welcome aboard.
Ishmael
Wow, did you make a BIG mistake asking that on this forum. We're more than happy to help you spend all your money!
As Ishmael pointed out, the absolute number one priority for you should be to take the Motorcycle Safety Foundation (MSF) Basic Rider Course (BRC) or one of the Rider's Edge courses taught at most HD dealerships.
Sounds like you've got the basics covered for general riding.
Here's some other thoughts:
1. Insurance
2. Cover if it's to be stored outside
3. Chaps, Draggin' Jeans, or some other type of riding pants
4. Rain gear in case you get stuck riding in the rain
5. Motorcycle specific luggage if you're going somewhere overnight
6. HD Service Manual for your bike if you plan on doing ANY mechanical stuff to your bike yourself
7. Lots of Pledge!!!