1) I think it's better to rent until you get your PPL, for two reasons. First, if money is tight, you don't have to worry about unexpected repair bills, and you can stop spending on it whenever you need to. Second, you probably will know a lot more then than now about what type of plane you want to buy.

2) Good question for an insurance agent.

3) I understand some planes and pilots prefer unpaved runways.

4) It would help to know what you plan to do with your plane, such as where you plan to travel, with whom, and why you'll be flying every week. And, what's available to rent in your area?