You won't be scaring away the seller, this is a completely normal thing to request and your broker should be the one prodding the seller's side for this info up front (especially if the seller's side hasn't provided it already with the marketing material at the very least). 

@Kunal Lakhwani, have you thought about a co-management relationship with a local real estate agent to handle the tenant placement? 

I will be moving to the Northern Virginia/DC area in a couple of months and would love to meet investors from the area as well as a real estate agent, insurance broker and/or attorney familiar with LTR/STRs.

Most markets the physical vacancy is 5-10%, good chance you can find it by googling and seeing what the average is.

When were are in a hot market we require a previewing questionnaire with 5 questions based around the application process - credit, income, pets, etc.

Sounds like you're in great shape to dive into the real estate world.  

Here are some practical strategies to help you navigate the process.Start by understanding the local real estate market.

Now it's a long term rental with under market rent which still nets 40% annual cash on cash return.

My name is Pete and I'm looking forward to buying rental property income in the near future as well as increasing my knowledge and education in real estate.

Alternatively, if there is a real estate agent/ Agency that anyone recommends, please let me know.