I'd probably use local realtors to help re rent any vacancies and then possibly use a PM software like rent redi to keep everything in one place.Has anyone had management in place and then decided to opt out to self manage?

If I ever plan to use a family member or friend who may not want to be fully involved in the process - what kind of documents would I need to provide that person that ensures their end is covered and could fully explain numbers, process, timeline, and security for them?

Its important to carve out personal outside space for each unit and make sure there is appropriate parking for both the primary home and ADU. 

If you can get insurance coverage and the local building department isn't giving you a hard time at all, then I'd say you're good to keep on moving forward with the deal. 

Currently living in Jersey but my wife and I are wanting to move to Florida to keep cost of living lower and start growing investments.

They might look at the LLC mailing address to associate it with a person, but you could always use a Registered Agent and the address would be different.

My question is: how do I start with little personal capital?

Wow 2.25% for 15 years.Can't believe this was even offered in the first place.Actually free money...If you're breaking even, I likely would just keep holding it.

There are certain rules regarding changes in use from investment to personal residence and vice-versa.

No sane person would do that and leave their bank account critically low for an extended period of time and keep the mortgage.