@Jon Passow I was in shoes like yours a couple years ago, desiring the same outcome and asking the same questions (though I had a handful of properties at the time, so had to consider existing REI assets). The route I took, in case it's helpful for you:
I had enough personal assets I wanted to protect. I created an LLC for my buy-and-hold property for two reasons: (1) I wanted asset protection and (2) it makes getting private loans easier - people equate that with "having a company" and take you more seriously. I decided against multiple LLCs - too expensive ($800 each/yr for state fees alone) and too complex (separate bank accounts = headaches for managing each property).
So I had the LLC. I went to re-title each of the properties and faced a dilemma (alluded to above). I have low rate, long term FNMA financing. I believe rates will rise. I count that financing as a key asset to my long term success. I can't accept risk to losing that financing. I wasn't willing to move title into the LLC name. I purchased additional umbrella insurance.
What I did do was move all of my property management functions under the LLC. This wasn't so much about asset protection as it was about appearance to tenants. And, clarity for bookkeeping and tax purposes.
While practical considerations prevented using the LLC for asset protection purposes, it has still be very valuable. Some things that it caused to happen:
1. It forced me to start doing real accounting (I use Quickbooks Online). Best process change, by far, that has improved my investing. I thought I was slick with spreadsheets and macros - I had no idea what I was missing.
2. I took a fast hard money loan for one project. The lowest rate lender (2pts, 7.99%) would only lend to LLCs. Because I had the LLC, I was able to make that happen.
3. Going through the LLC formation motions taught me how it works. As I moved on to bigger and more complex projects and raised capital from outside investors, I leveraged that knowledge and have had to create other entities for other purposes. Though my initial actions were naive, the knowledge I gained set me up for bigger things.
TLTR: I'm glad I created and now operate that first LLC, but it isn't really providing asset protection like I thought it would.