Hoping to set things straight with rental properties

[Robin W.]

A parent split down payments with me after receiving an accident settlement at age 18 to co-own two multi-fam properties located in different states. But now over a decade later, I realize they've not been managed properly and as an wiser adult I'm setting out to right that wrong. 

I've never missed a mortgage, and have happy renters in all units, but I agonize over the lack of pristine account books, and not knowing if they are better off in an umbrella policy and land trusts, or if rather organized as an LLC.

One huge stress factor is that I solely pay property taxes, maintain and manage the units, and keep them rented while my parent routinely demands the split partnership if sold. It's a recurring, uncomfortable discussion as I intend to hold for the longterm, and moving on as an adult with marriage and my own investments. 

Where should I begin to tackle this issue with grace?