Is there a way for me to pay for use of the software and state filing fee before I file? (I am still waiting on one more tax form that will not be ready until March 5th)

You can pay for your TurboTax online account fees now before filing. 

Click on File on the left side of the online program screen.  On Step 1 review your Order Summary and continue

On the following screen click on Pay with Credit Card to start the payment process.

Thank you