Financing a 50% vacant 16-family

[Alan Corey]

I own several 2-families and a 4-family which I was able to acquire all through conventional residential mortgages.  This will be my first time going the commercial lending route and I'm running into some nuances I'm unfamiliar with. 

I'm looking at a 16-family that has 50% vacancy.  The seller says the deal has to be in all cash as commercial lenders won't lend if it's 50% vacant.  A couple of questions on this if you don't mind helping me out:

• What is the cut-off for vacancy for lenders to provide a loan? 70%? 80%
• Even being 50% vacant and assuming a 30% downpayment on my end, the cash flow would still be positive and I would imagine appear low-risk to a lender
• If I buy all cash, would refinancing and cashing out have the same terms?

Thanks for all your help! Long time lurker, first time poster.