Mortgage, or cash and refi?

[Martin L.]

I'm looking to buy additional properties, but on an indeterminate timeline (never know when a deal will pop up), and I'm wondering if it's better to go through the mortgage dog and pony show or just buy cash and refinance after? I'm leaning towards the second, but wondering if there is any drawback to that (ie. higher rates or harder to refinance than getting a mortgage from the get-go). Am I correct in assuming that if I get a pre-approval letter from a lender, it's only good for about three months, after which point I will have to get a new one with additional credit hard pulls?

Also, will a lender balk at refinancing if I used too much of my cash reserves to purchase the house in the first place?