I keep them around the 50% for 30 days mark with last minute guests filling in the spaces and increasing my occupancy.

With the goal of building equity and doing renovations to increase the value of the house, does this make sense?

First, I commend you for taking the very first step in your real estate investing career...and that is reaching out to experienced investors on BiggerPockets for advice and guidance.Second, you are in a great position with your credit being the way it is, the money you have saved up, and the increase in salary at your job.What I would do if I were you is to take this time (since you've been in it all of one month or so now) to learn everything there is to know about real estate as it relates to the niche you are trying to pursue.

See numbers below...Purchase Price$121,000Rent$1,200Appraised Value$125,000Mortgage Balance$93,553Vacancy$100.00PITI$746.97Maintenance$50Future Cap-Ex$100PM$120Lease Fee$83.33Total Monthly Expenses$1,200Projected Cash Flow-$0.30I'm interested in possibly refinancing to reduce the mortgage payment (increase the cash flow).

Keep in mind it will be a 12 yr variable with a balloon payment due but that's not bad at all even if rates increase. 

The rising property value has increased the taxes to the point where it is eating a lot of my cashflow.

Our commissions increased based on the number of loans closed per month, and the volume of those loans.  

Here's my thinking.The cash flow, ROI, and potential margins from Multi-Family seems to consistently outweigh that of single family- from what I've calculated- without a great increase in investment total or difference in sale value.

That process doesn't work if you buy a nice house with a maximum LTV conventional loan because you've done nothing to increase the value.

I may pay more up front, but everything is updated and I am financing it over 30 years, so it is just increasing my monthly payment.