Additionally, for the AR llc, do I need to register the LLC in California as a foreign company?

I don't think US based banks are allowed to accept any foreign currency as is (deposits, payment).

You’re not buying ownership, but you’re securing a share of the cash flow, which can be appealing for passive investors.For property owners, the trade-off is receiving immediate liquidity in exchange for sharing future cash flow.

Or we can just exchange contact info.

You will have to 1031 exchange.

One thing I'll add to an off-market deal is you might find a seller willing to do seller financing.You said, "I don't think the time exchanged to manage SFH would be worth my time and the cash flow most likely wouldn't be reasonable enough to hire a property manager.

I know the IRS asks about entity vs personal members and if they're foreign or not specifically on the 1065 and other tax forms. 

Total investment: $420k, with a 1031 exchange offsetting $300k. 

Have you heard of Exchangers? 

And the condo debacle in FL will be churning for quite a while as these rogue HOAs try to get realistic with deferred maintenance, new requirements, and freedom for people to use as they need to afford them.One thing to consider would be to 1031 all of them in a consolidation exchange.