I have spent the last year working two jobs to save money and at the same time improve my credit.

Do you do background check and credit check also?

If so then you may be able to get 90% loan to cost depending on experience, credit score, loan amount etc...

My credit score is around 750, and I got pre-approved for 330K at 4.5% back in May.

You can also have your prospective tenants pay for Credit/background checks via Cozy, as well.

i would go with former tenant, however I would still have them do a credit/background check (at their expense using something like SmartMove). 

Ideally you want to get to the point with your buy and hold operation where you have enough surplus cash flow coming in each month where you can cover a line of credit for your properties.

I'm seeing that a lot of banks and credit unions require minimum 6 months seasoning before cash out/refi. 

If you are not selecting them because of credit reasons you must formally notify them in writing of the reason and also the credit reporting agency that you used. 

This morning I called my insurance agent, he was most cooperative, he called the local police to get a case number and said this is by now a famous incident!