I essentially want to have a W2 job more as a hobby and rely on my rental income to reach financially freedom.

I remodeled the kitchen & bathrooms.

If you only have 1 bathroom in each unit my opinion is that gets tricky. 

I need a color for my walls, living room, bedroom and bathroom.

If he is hiring you to find him jobs, you would essentially be marketing for him and getting paid based on what deal structure you work out. e.g. percentage of the job amount, fixed finders fee, etc.If you are starting your own contracting business, you would need to defer to TX small business laws.

Is it O.K. liability wise, to have a handyman:Replace a bathroom light fixture.Replace a ceiling fan.Replace a switch.Replace an outlet.Replace a standard screw in lightbulb.Repair a loose outlet box.  

Have either the kitchen or bathrooms recently been updated?

I am doing rehab for a duplex currentlyFoundation repair: Slab foundation in between 5k to 8kRoof: 12 - 18kflooring: 2 - 4 per sq ft including materials ( of course will be higher for higher-end material)_kitchen cabinets and countertops installing labor: 300 to 500$Redoing entire bathroom: labor: 800 to 1500 Feel free to PM me for any more details.

I have heard and read many posts about how reliable cleaners are essential for STR business.

I wanted to add a bathroom to each unit and update the kitchen and existing baths.