Wow, you have lots of questions, and I don't think I can answer them all effectively. Bigger Pockets has lots of great articles, podcasts, and forums where you can go and read up on many of the things you mention.
The first step in any new adventure should be education. Learn as much as you can, first, then execute.
in general, it can be better to use someone else's money to do deals with, instead of your own. But that depends on you, and what your plans are, how much $ you have, and your tolerance for risk, and so on.
Any good banker can get a loan together for you on a good deal. They will put the closing fees, and possible rehab costs into the one loan, as long as it makes sense for the bank. Some times doing an interest only loan like this will keep your initial payments low, while you complete the rehab, but then they will want to be paid off at the final closing with your retail buyer. Hard money loans can work for this too.
My advice: hang around here on BP, and look around a bit. then you can start looking at possible deals, start putting together a team of professionals that you will work with you (banker, hard money lender?, contractor, lawyer, cpa, etc...). Then do it.
Good luck, and I hope that helps a little.