My goal is to build a solid portfolio of rental properties and supplement the portfolio with fix/flip profits.

:Should I 1) sell now, reinvest and get a better cash flow immediately (after a break even investment over 18 months); 2) hold off until I can sell for atleast some profit, or 3) Sit and wait (buy & hold)...and assume/hope appreciation will come though in a growing market near Austin (keeps some diversification as well)Id like you hear some feedback.

I would suggest looking around and seeing what kind of companies operate in markets you may be considering.Try looking at:What to Ask When Working With a Turnkey ProviderandThe Best Types of Markets for Profitable Turnkey Properties

I've found that, once a property hits any list, it's already picked over and there's competition because others also have the list.The best wholesale deals are properties you can buy very cheap in order to resell low enough that an investor can buy it from you and still make their own profit.

That may be something I will look for down the line though once I have established a profitable history. 

In other words simply delaying paying the $120k tax for 10 years reaps you a $259K additional profit at 8%. 

There's SO MANY ways you can buy properties without banks and still net a killer profit and/or killer cash flow. 

It's an 80/20 split until a $16k cap and revenue share (not profit share).

One of the deciding factors is will I have to pay 20%-25% in property taxes if I roll the profits into a new multi-family property? 

At the end of it theres a 50/50 split on the profits.