Some even when buying incorrectly will be able to handle the next down cycle and wait it out.It's the buyers who overpaid and can't hang on where you scoop up deals.

Are they liable for the total rent amount, the initial (incorrect) lower rent amount or the higher rent amount that Section 8 would have required the tenant to pay. 

I would calmly explain you have changed the locks and the old tenant does not have a key however if he feels uncomfortable (and people have their quirks) either offer to change for him or have him document a locksmith changed and give you a key.  

Incorrect.  

Hard inquiries stay on your report for two years.If you find incorrect information on your credit report, contact the agency upon whose report it appears, and ask them how to get it dismissed.

If this is the incorrect way of doing it, let me know.

If I am incorrect on this assumption, please let me know!

Don't get upset yet,instead get a second opinion.Have a non VA appraisal performed to see the differences between them and the data that was used to come up with the new price.If you truly believe the VA appraisal was conducted incorrectly due to using incorrect comparisons,you can use the new appraisal as evidence when you appeal to the VA appraiser and their immediate supervisor.

However, keep in mind that they only collect data from Airbnb, so details such as occupancy can be incorrect if the owner lists on multiple platforms (most do).

MLS information on REO properties typically has many bits of incorrect information.