We plan to spend half the year there but I don't want to incur a penalty (or whatever bad happens) if we do not meet the exact 181 days. 

Make it an either or if you half to, they can refuse a new lease but they can't refuse a 30 day notice to vacate.

I have a few follow up questions:1) It sounds like you're saying, if the seller gives the 90 day notice to the tenant so we can occupy that half of the duplex, we can close approximately 35 days after that and be in a 60 day window and satisfy the VA loan requirement? 

I am currently running my parents Airbnb's as they have 3 of them (working on expanding) and have been fully managing them for the past 2 and a half years.

Half of them asked me if I had any ammunition or guns for sale. 

Shortened  this wall to open up the home and added a bar top to this half wall.

I’m glad you mentioned that point, and I fully realize real estate isn’t a half-in half-out game.

I can’t believe someone would pay $700/mo to live in half of 1000sf. 

Over half of my units are priced so that a they are affordable to "low-income" renters and over half are one bedroom units which probably is part of the reason why I've seen a relatively high application rate.

If you’re both equally responsible for the loan, does only half the PITI count toward your personal DTI, and the other half to your partner?