Adequate insurance is generally recommended as a first line of defense and may play a part in this decision as well. 

I have no clue if she talked to any buyers besides myself at any point but without playing games I told her I could pay her what she asked for.

A lot of investors seem to be buying in here as long term defense plays.

Mailers are long term plays, expensive, and have a low success rate.

Defintely talk to a lender because there are a ton of factors that will play into the amount of next mortgage you can get- the biggest ones I dealt with were DTI ratio and the monthly payment I would have to make on that HELOC.

I wasn't playing any music, I was sitting working on my computer and there was no noise. 

Unfortunately the building I bought in does not support STR but I still think its a solid play as a regular long term rental.

And it's completely up to you and the amount you are willing to spend.If you are planning on making real estate a long-term play then you should definitely be on the hunt for a good accountant and attorney. 

If you're using your credit cards to invest in equities, that is a very risky play that could really bite you in the butt.

So, ideally that would be a cash-out refinance of your personal home to the highest LTV you can get on a conventional loan and then moving to a home that has an investment play associated with it (a house-hack or something else).