Glad to find you're having fun playing CF. It's my favorite.
1. Like any other Animal Crossing game, you would have to make more players in order to create more patterns.
Hopefully whenever the next non-spinoff AC title will either add more slots or have some type of efficient organizing system.
2. Impossible to get exotic fruits without using an external tool. If you want them and don't mind hacking, try ACToolKit. But if you want it as genuine as possible just place one exotic fruit on the ground near your house and work your way up from the game. The process of getting ACToolkit is extensive anyways, I don't suggest trying it if you're not tech-savvy. Exotic fruits not only make your town more outwardly interesting but each fruit is 500 bells. You can get a coconut without hacking, however, but it's an uncommon event for one to wash up on your beach. Summer, right now, offers the most profitable bugs and fish, including sharks and beetles. Red snappers are 3,000 bells a piece and are available all day every day.
3. Sorry, no. Sucks not having the benefits of WFC, right?
4. Have the shops for a certain amount of time, and buy items at a certain amount of total cost. The upgrades should come naturally.
I hope my late advice helped c: Oh, and turnips. Red turnips were removed in NL. I would stick to the regular ones.