I still have as of yet to do the build up on my current K5, and it's been a little while since I did some real wheelin', especially at night, but I'll post my 2 cents.
1. I used to do a lot of night wheeling
2. Every weekend, with some week nights too (about 80% of my wheeling, back then)
3. Not on the current one, but it will. My old one did.
4. I had KC hilights, not sure what I'll go with on the current K5. I also had some cheap kc knock offs for some back up lights.
5. Not sure, I think I may have gotten them used, and it was many years ago anyway, so it doesn't really matter.