Same exact process. 2-3% is a good estimate for closin costs. If you want to escrow taxes and Hoi keep in mind you will need to fund the acct.
What's your current product? 30 yr fixed? Bourn probably knows better than me but rates were recently at a 5yr low and the rate on a 15 will be less than on a 30. I would recommend googling amortization scheduled and finding out what the breakeven is. In regards to pmi at 80% you can call your lender to have it removed. At 78% it will automatically fall off but I'm not sure ig govt loans are the same.
You can get high 2.7X or 2.8X right now on a 15 year loan, or you could in July at least. I also am not exactly sure when it will drop off on some of the newer FHA loans, I believe there was a program started in teh last 2-3 years that is WONT' ever drop off unless you refi. Which is high way robbery but the government forced it upon banks ot offer.