Many times I've asked a neighbor to share in a common expense and they were relieved I had a solution to something they didn't know how to address or even that it could be addressed. 

Yes, I assume you will use tenants in common hehe.

Randy, it is a single family and I would be renting 1 bedroom and the only other full bath as well as the common areas of the home.   

Quote from @Stacy Eisenberg: You are making a very common mistake.

Building the common connection/story that allows for you to relate to and build trust with your dream investor avatar3.

And are there any common pitfalls or crucial advice you wish someone had shared with you at the beginning of your investment career?

When you say only a JV and not a new LLC formed do you mean you are both on the title as tenants in common? 

How much they can bill is slightly subjective, but the most common lifespan for carpets I hear is 5 years, with some saying as low as 3.

I feel like this is suchhh a common question for new house hackers, including myself. 

I know these laws vary widely among different states, but the common law right of equitable title in Virginia goes back a long way and I suspect it is not undone by this updated definition in the DPOR regulations in Virginia--even if that is what their intent was in trying to change this definition.