Welcome Wheels.

First, I think your thinking with regard to your best initial options is on. Bugging-in and using your vehicle to the extent you cannot are for most of us the right ideas to begin with.

I think the ideas reflectors and lights to make you more visible are good too. I had a bike light when I useed to ride in the evening that flashed like a red strobe. I'm sure you could find one, and I'd use both a light and a reflector or two. If the light fails, you'd still have something making you more visible.

One thing I think you should think about is what happens if you need to bug out and your vehicle is not an option. I like keeping as many options open as possible and considering the worse-case scenario.

Do you have supplies in case you want to bug-in at your office or elsewhere? Having a small amount of supplies or a backup kit might be a good idea. More is usually better, redundancy is often not a problem.

I little knowledge about maintaining a wheelchair, but do you carry any spare parts and/or tools for it?