Main problem is, there is what looks like 1-2 feet of still dark water sitting in the basement ( completely concrete unfinished basement no drywall or flooring).

What are the benefits of buying from him instead of going to a realtor because he is not willing to cut me a better deal than anyone else in the area including a realtor.

You may have some tax benefits from a LLC, but that is secondary to the AP part of it. 

I was mainly thinking having a higher income would be more beneficial in securing loans and scaling faster, and there could be a possibility that the market would cool off by then.

Usually price and pictures/curb appeal will be the main factor in getting people in the door.

You are correct that most tenants aren't that picky about new windows, but there are benefits.   

I had a great conversation with @Kay Kay Singh today about the depreciation of gas stations, and thought I would share some relevant information regarding the tax laws for the general benefit of the BP community.Gas Stations (or 'retail motor fuels outlets' as they're called by the IRS) are depreciated over 15 years, and not 39 years like almost all other commercial properties.If any one of the following three criteria are met: It is not larger than 1,400 square feet. 50% or more of the gross revenues generated from the property are derived from petroleum sales. 50% or more of the floor space in the property is devoted to petroleum marketing sales.Here is the link to the IRS publication on this subject where the above words were take from.

Stagger the end dates so you never find yourself with all three units going vacant at once.Another benefit of having them sign a new lease.... you can raise the rents if they are below market and immediately give yourself an enhanced return on investment.Good luck

Why would you tell your banker, unless there would be some advantage/benefit doing so. 

I've been reading insurance is the main issue with having a unit like this, as they can void all coverage.