Usually buying a car outright is a better deal if you can pay upfront without a loan. If you do need a loan, then depending on the deal you get for the loan vs. the lease it can be a better deal to lease, but not usually.
The greater the down payment, the more favorable the terms of the loan/lease.
It will be hard to get a loan when you have bad credit. However, if you already have a loan and have bad credit on other things such as credit cards, then keeping your payments current on your loan can help improve your bad credit over time.
The first thing a business owner should do is to meet with their lender or banker. Often if they are a good customer, they will rewrite the conditions of your loan or lease to help the business owner.
It is essentially the same but of course with a lease, your responsible for an amount agreed to be paid rather than paying back a loan.
It depends on the bank. However, if you rent it out, you will need a current lease and perhaps proof that rent is being paid, like cancelled checks.
The Loan and Lease Act