Community property with right of survivorship should avoid probate at the first death, but what happens at the second death, or simultaneous death like a car accident? 

It's not a chicken and egg situation either way, you have to do both simultaneously.

That is, with both happening simultaneously where might I get hung up?

I'm buying a duplex in Jacksonville Beach, FL that has been legally separated into two separately titled townhouses, which means I'm currently going through two simultaneous purchases with two separate sellers (ugh). 

I tried but had a triple simultaneous closing all on the same day.

@Jay Levy, A simultaneous swap can certainly be done and it can be done without the normal QI involvement with the 1031.

I don't buy anything unless it will cashflow and I can grab at least 20% equity simultaneously.

Three back-up offers in an hour, and they took ours first, came back and said, raise it $1000 and we're done, no simultaneous bids or anything.

As title states, I'm curious to know how many rehabs you have done at one time simultaneously.

It seems like the reasonably priced ones (near or at market) are closing simultaneously with listing?