You will find that over time the more properties you own you will no longer qualify for standard mortgages and you will have to go through a commercial lender.

Usually that amount is less than the agreed amount and a buyer won't have the equity they think they do and fail to qualify.

There's really no reason to bring it up in the conversation you have with your loan officer unless a good part of your qualifying income relies on that license.   

I always try to discuss these points with them on the first phone conversation before we even meet at the property, I don't understand why so many still look at a property and waste money on application fee's  when they should already know they will not qualify.

Have you been pre-qualified?

My concern is if I tap into my equity to get the down payment money that the payment on my heloc could keep me from qualifying for the mortgage on house 2? 

Both sides are 2/1 w/ an additional room and about 850 sq. ft. a unit.Any advice both on how to find/ keep qualified contractors and any idea on estimated renovation costs?

There are plenty of other issues like hiring the wrong contractor, zoning/permit issues, helping buyers qualify, poor design choices, etc., but the bulk fall somewhere within those three buckets. 

Get pre-qualified for a mortgage around January 2017 (must wait until the same calendar year as purchase, correct?).

I need to build my credit history starting with secured credit cards, work up to unsecured cards over the next few months before trying to qualify for mortgages with US banks later this year.