If I choose to not renew and there are damages or he doesn't pay his last few months (he has about 3 months left) what are the simplest actions to take to collect the rent owed or money for damages?

Feel free to pm me and I can provide their contact details.Sounds like a solid plan to me, now, just have to continue that daily consistent action to put it in place. 

I have spent the better part of a year learning as much as I can and feel like it's time to take some action. 

It discusses the art of neutral thinking and overcoming challenges by getting to the truth to determine action.

Just like the folks on BP encourage partners without money to apply a skilled trade to get into deals, you're offering the same thing with development.  

other investment opportunities (other than a flat out loan at a favorable interest rate) seem pretty fraught with peril as you will need your sister's consent and participation to take any action that would allow you to realize any gain, including a refi or property sale.   

Despite the volatility, I’ve averaged about a 200% annualized return on my Bitcoin over the last 9 years, so I definitely don’t want to trade it for another asset AND be taxed on it.

And what course of action would you recommend? 

The trade off, in this market in particular, is most good deals are going quick, all cash, no contingencies.  

Here is a trade secret for situations just like yours.