(full disclosure I am already working with an agent, he's actually already part of this discussion haha) Ive done cosmetic rehabs in a month, Ive done full guts in 3.

If they are purely cosmetic, I'd leave them off. 

What I do know: asking price is $300K, units rent for $300 a week, owner owns free and clear, per owner building on needs cosmetic repair, units are walking distance to the beach.

Here's the first one which definitely needs some cosmetic work on the exterior https://www.redfin.com/VA/Hampton/9-E-Cummings-Ave-23663/home/52046211And the secondhttp://www.realtor.com/realestateandhomes-detail/1203-Victoria-Blvd_Hampton_VA_23661_M54776-86930

Appraisers look at a ton of factors including bed/bath count, square footage, acreage, neighborhood, etc. and the cosmetic condition is only one of many factors.  

My question: Do I need some kind of permit to make cosmetic changes to the house? 

For example, a borrower that only needs 50% of the ARV on a cosmetic rehab in my market is far less of a risk in the loan that someone who wants 75% and is then bringing in more of their own capital for the rehab, so maybe make $5k off the deal, if everything goes smoothly.

But there are still a bunch of mismanaged properties or properties that just need some light cosmetic work to jump the rents up, you just have to dig a little more than before.  

No cosmetic repairs, only necessary repairs.

I lived there for two years while doing light cosmetic upgrades.