They move it to deals that throw off an acceptable return for their money.

This will hopefully be the last communication before an accepted offer.

I have an accepted offer of 185k net to seller with seller covering 7.5k of the closing cost.

That leaves nothing allocated for the other costs.I suspect you are going to find it difficult for someone to accept a cap rate evaluation because 1) their financing will not be based on a cap rate evaluation 2) you do not have the actual NOI that would allow a cap rate valuation.The cap rate valuation is not likely to work even if you had NOI because this RE does not require commercial financing. 

You have to accept being 80% prepared, and trust that you and your team are good enough to figure the other 20% on the fly.

I'm running numbers using the BRRRR calculator, and I'm finding deals given (keyword, given) my offers get accepted.

They put one up for sell on the MLS, then had to remove it from the MLS it as it was occupied and no access was allowed, but I had already put in a bid which they accepted. 

Online deal, my offer was lower than the asking price and took a little time before they accepted it.

Institutional lenders are only going to typically accept deals where they are the only lien on the property

If their motivation to sell is high, they are more inclined to accept an offer below what the property is worth.