Last I did their rates were 1-2%. 

Would a bank(say like BankofAmer) allow me to assume the low interest rate of another property and blend the interest rate with my current rental property?

and unfortunately, with rates and prices high, it has just gotten very, very tough to cash flow on long term rentals.i browsed a few other threads you started and it sounds like you already own your primary residence and are looking to get started in investing. 

You’ll get an automatic 20-40% discount (tax deduction) off the rates which might make doing it yourself not worthwhile. 

Im looking to do a STR in Ocean City Maryland and the vacancy rate, if I'm fully booked in the peak season (May -Sept), would be  58%!.

Each lender, for the most part, is going to have similar rates. it really comes down to communication and their process!

Insurance has been a big issue in our market this year as companies have jacked rates out of control. 

Lending could be an option but with interest rates high 7, I am looking for other creative options.

The terms of your mortgage and interest rate will remain the same and no refinancing would be required.

In the vaguely unlikely case that the cap rate and deal is real and there aren't any significant "gotchas," 25% down should be easily doable.