They could very well be common in higher price points in my market that I'm not as involved in, but they seem like a foreign concept in my experience in the $125-425k range above and below median price.

However, if I open one in Florida, I can be my own registered agent, but I'm wondering if there are any drawbacks to being a "foreign LLC," when my rental is in another state.

Oh I see foreign national.   

My llc is in florida and i have property in nc , i must to register as foreign? 

Hello,  Your friend should look into foreign national mortgages. 

Other talk is foreign to them but everyone thinks they know everything.

That would allow you to assess whether the sections were big enough to build another property on.Also even if you do have the funds available to purchase a property there are foreign investment rules in place that make it difficult for overseas investors to purchase.

A reminder, when we military have occupied a primary for 2 years of of 10 years, we can exclude capital gains on the sale of that house: If you or your spouse are on qualified official extended duty in the Uniformed Services, the Foreign Service or the intelligence community, you may elect to suspend the five-year test period for up to 10 years.

You can have both asset protection and separation but you will have to have either one California LLC or one foreign entity registration in California depending on where your investments are located. 

What does a "foreigner" need to be aware of when attempting to profitably manage STRs outside the U.S.?