It's not the personal debt guarantee that exposes you to risk: it's ownership interest.If you have a $2 million liability policy you're going to be fine even if the LLC does get pierced. 

I also think that is good policy, as we don't want to see a pandemic take away lots of people's homes. 

Call some local independent agents and get a quote on a rental policy.

I cotacted the owner the morning she listed, virtual toured the property (COVID19), checked w the HOA regarding rental policies, made an offer based on my numbers, and she accepted.

The lender that told you HELOCs are capped at 85% LTV was only speaking about his bank's in house policy. 

Most of my clients buy strong suburban with better cap rates and low prices while still getting investment grade tenants.There can be some valuable land plays in both strong suburban and urban core areas.Ability to rebuild will depend on quality of the insurance company and policy and what they try to exclude.

If you need the cash flow for your monthly living expenses then yes, of course, but if you're buying the property for your retirement 20-30+ years from now you get so many other long term benefits not achievable by other investments.Your insurance rates may have been factored for homeowners insurance vs a landlord policy (property & liability).

His only request was that I take out a life insurance policy equal to my half, basically, or equal to what he loans me if we don’t actually partner, and make him the beneficiary.

I am a fan of a good umbrella policy.  

Insurance- most storage unit insurance policies do not cover vehicles.