I haven't heard of the bi-weekly credit card payment idea.

Don't just be enamored by double digit returns and definitely don't feel rushed into investing in any funds. 

I can’t say I came up with the idea, I saw a landlord with more units than I have post that they offered the holiday discount, bug only to their tenants who had made all their rent payments on time and in full over the course of the year.

I will be graduating with a degree in Digital Marketing and have been applying to jobs for a while with not much luck.

Then you can talk to the mortgage company or payment processor yourself. 

I understand that if I rent this ADU out, then I can have a tax write off on the mortgage payment and insurance payment for the the ADU's sqft portion.

.- My Resources / Constraints: I'm in a by no means unique, but perhaps less common situation for those getting started; I'm a somewhat senior software engineer at a tech megacorp and should be able to save a couple of down payments per year for lower priced houses (100-200 in my area), or perhaps one medium priced house (300-500).

That allows the payment to be low, manageable and easy to cash flow when you transition it into a rental.When you move out you will have more money in the bank, stronger assets, and be cash fluid in case you need to make an offer on more investment properties.

If rates drop in the future, refinancing again could lower your payment, but it’s good to make sure the numbers work now just in case.

Before you ask, No, they will not make any back payments.