I had hard money for the purchase and got a personal loan for the rehab (half the interest rate).

Or would a non-voucher / market rate tenant pay $2,800 to $3,000?

When interest rates are peak high I started my first investment and was able to cash flow !!

As Nathan said, for an MTR - expect their rate to be 12-20%. just be mindful of such!

I almost want to just hire workers full time at an hourly rate and have in the contract they cannot take other jobs until mine is done.  

Should I try to save more money and improve my credit for a better rate or try to get creative financing for my possible investment.

Rent rates have probably tripled in the last 20 years.

But there is no visible building on Google Maps, and Xome.com states 0 square feet for the structure.Big red flag: I got it for 16%, the maximum interest rate in an interest rate bid down state.

Assuming FHA or VA loan at lower rate , although I need to cover current equity in home?

If you're hoping to wait until interest rates come down, not only do we have no clue if or when that will happen, but when it does you may see prices go up as buyers are able to get larger loans.