Your appraiser can’t possibly know everything you’ve improved just by the visual inspection.

If they ask, I would let them out of the lease.If you want to give them a bathroom and are prepared to do it now, I would get comps for rentals with 2 bathrooms, and get an addendum signed that once the bathroom is functional the rent would increase to the rents of a 2 bathroom house.   

The variation in price is a function of their business model: where are they securing their inventory and at what cost, what are their labor, marketing, and other business costs, and what profit they desire.To your specific question, "yes," the bank can basically offer whatever number they want.

Recently purchased an old but functional duplex which we will rent to some long term tenants.

I like realist.Deal machine has a lot of youtube videos so you might can check features and functions there.Not sure about the two you mentioned.

Can i request access to a visual inspection of the house?

the The Tesla superchargers are by far the best as they charge far faster than any of the others are much more reliable and you dont have to pay at the pump as it were you just sign up on the app with a CC and your automatically billed and then on your multi function display in the car when your done it tells how much you spent. 

They have MUCH more functionality than you need.  

Is there a platform out there that I can see my properties in a visual way and see how they are doing by the data I input?

If you are staying in an a place for 2+ months, you don't care as much what it looks like, you care that it is comfortable and functional.