If your main mortgage lender has an IQ greater than like 95, then you can borrow against your 401k, and it will not be viewed by your lender as a loan OR impact your DTI.

I was able to view the rental when the previous tenant left it in pristine condition.

Hello, I will be going to view a potential property for my first investment in a few days.

Again, it's a seriously hot market, so you will have to have a local team to view and vet properties for you.  

As you get closer to city view dr- house prices are a bit higher/nicer homes. 

For example, if we added a 4th partner who is based in Atlanta to live in the property for a certain period of time, could the loan be viewed as a regular way mortgage versus an investment mortgage, resulting is us having to put down much less than 20%?

You need to find a good property manager that will put your property on the list for tenants with vouchers to view your property.

This will straddle two tax years and that's another situation that will work to your advantage reporting wise and is a phrase that tax courts have used in the past to describe a valid exchange.  

I am now in a position that realistically I should be able to view homes and put in offers by the end of February/early March at the latest. 

The definition depends on a person’s point of view, but the end result is the same.