IF YOU SELL YOUR GOOD UNLESS THE Buyers ARE FHA QUALIFIED WITHIN 90 DAY Rule comes Into Play.THERES MORE BUT IT CAN GET COMPLEX DEPENDING ON YOU PLANS.

Abandoned property laws may still apply, depending on your state regulations.

I'm not sure, I suppose it depends on what that $1910 number includes. 

That said, in larger cities, an STR may only be approved in one part of the city and not another (street specific) depending on proximity to a hotel/resort.Obviously lots of due diligence needed.

My wife is a realtor so thinking we would drop the 3% commission from closing as a way of negotiating down the buy price since we need our mortgage payment on the new home to remain very close to what we are currently paying today (so that our life living costs remain within my salary/income so not depending on my Wife’s non W2 income Realtor income).

This depends on what you currently hold with the seller.

Mostly done by a lawyer depending on where you live and a title company.

The exact nature of your legal situation will depend on many facts not known to me (us) at this time.

Whether or not the seller can back out depends on the contract you signed but honestly it's a free country and it's still their property, no one should force somebody to part with their property if they don't want to.

I always think about the value of the repair on different levels and start in a stepwise fashion 1.