Hi James, welcome to the site.
Here goes my effort on answering some of your questions, just my opinion btw.
1. Not quite sure what you mean here. Settle the finance when you sell the car, or how long to get finance to buy the car? Either way your best bet is to ask whoever you take the loan out with and they should give you an honest answer.
2. Personally I would go for HP as at the end of whatever term you decide to take the loan over, the car will be yours, unlike PCP where you will have a ballon payment at the end, which more than likely will be the value of your car. Also you will be limited by milage with PCP and the charges for going over are very expensive. However, PCP will generally give lower monthly payments so it all depends on how much you want to spend a month and how long you want to be paying the loan for. If you don't do that many miles and are confident you won't go over your estimate, then maybe look at PCP. Personally if I was financing a car I would still go with the traditional HP for the above reasons.
3. I have never dealt with Motorprovider so would not like to comment. I would recommend you search the internet though for personal loans as these generally provide better rates than dealers and there usually arn't any hidden charges like at the dealers. Also they usually give you an answer straight away over the net. Provided you have a good credit rating, all the major lenders should give you a quote.
4. I would always pitch up at the dealer for a face to face, IMO you have a better chance of getting a good deal and can also put your point across better than on the phone. Never trust dealers as they're out to make as much money as they can from you.
5. Again, dealer dependent, best to ask them that question.
Hope this all helps.
