1. When I was started, four channels was ok. Eight channels was expensive thing. Now, eight channels is something pretty standard for recorder.
2. Four wireless is ok, if you want more you can rent.
3. Mostly two shotguns. That's a big discussion which brand (lol).
4. I am using Ambient QS boompole, 5.2m, but I am doing mostly scripted work.
5. Timecode, IFB, camera hop is necessary.
It's not a good idea to start with a loan, especially that time. You buy only when you needed something or when you have the money in your pocket - playing safe business risk here. I know, US market is different from mine, but others can guide you better from me for that market.
If you want to discuss further which type of brands, please let me know.