I MUST achieve financial freedom to spend as much quality time with my only remaining child (15 yr old son) and travel as often as possible to aide in my healing process.

Broken sliding glass door, broken window, broken kitchen cabinets, child scribbling on the walls and a broken medicine cabinet.  

Don't let that scare you though, I've had clients negotiate $20k off the selling price, and I only charged them $10k for the deleading, so it can actually work in your favor for it not to have been done yet.You also cannot rent to someone with a child under 7 unless you have a lead certificate on file with the state.

High tax rates, child care costs vs staying home, commuter costs, time to grow RE investments. 

I love Mexico and have been going there since I was a child, I have thought about it for so long.

The tenant upstairs tenant has a young child who plays during the day which contributes to the loud noise.

Child 1 LLC owns the property, Child 2 LLC manages the property.

There may be different state/local laws giving more coverage to the tenant as well.That being said, if this child has a genuine need - ask for a letter from his doctor (that is legal in housing situations) - and this dog is an actual service dog that has been trained to do tasks for the boy (things that he needs help doing, such as walking or picking up objects; just emotional support/hugging/petting are not tasks and do not make a dog a service dog*), it would be the right thing by you to allow the dog even if the law says you don't have to.

When they brought each child out, all the kids complained about being in the room with much to do.

I would recommend one LLC per property or using something like a series LLC where you can place the properties into individual child cells to minimie liability. .