Based upon your numbers the cap rate is fairly low ( 7% ) meaning over valued .

What does it mean when a counteroffer says this from the listing agent: "Buyer shall be credited $10k for escrow fees and other fees."

The rates and terms for many are still fairly decent allowing you to achieve the ROI from your duplex purchase. 

Brad Swaney this is a commercial loan product and is fairly standard I guess.

Once you accept someone with a so so credit or start turning a blind eye to things that pop up on background checks or income requirements, what you do for one you must do for all. 

Why not re-offer 350k with a 100k seller credit (for example) and use that credit for down payment and closing costs when appraisal comes in at 370k like you feel confident it would.

If they are VERY professional, they will have their processes in writing as verification that it is enforced equally and fairly by their entire staff. 6.

As a result there is a very real danger that hosts will be penalized, receive bad reviews on social media, and even lose their accounts on Airbnb/VRBO which could quite realistically cost them their businesses if no consideration is given to grandfathering in owners and hosts who are already operating more than one STR per lot, not to mention it seems fair to give owners and tenants a chance (as was mentioned) to recoup their significant investments (as one neighbor mentioned--her life savings) which they made under the existing laws." 

Investor, you're gonna go in there with your 65% offer after they have a moderate/fair offer from these iBuyers?!?

I was a carpenter for several years and enjoy getting my hands dirty - the plan is to be the owner/builder, sub out a fair amount of the construction, but add value by doing a fair amount of the planning and some of the building myself.