So, here I am a new investor with a long path to cover and business plan well designed with the niche that always caught my attention since I was a child and knew Real Estate exist, "Buy & Hold".

For learning purposes, you might want to pick up J Scott's book on flipping - it was a big part of how we designed our business model.

Awesome design. 

Lastly they needed a confirmed quote for homeowners insurance.

That said, do you out of courtesy give the tenant a heads up and set an appointment on a specific day, at a specific time and request that the tenant (or at least somebody over the age of eighteen whose name is on the lease) be there in person during the "Maintenance Check",ORdo you just show up unannounced, knock on the door/ring the bell loud enough to be heard and let the tenant let you in and then proceed with the "Maintenance Check",ORshow up unannounced, knock on the door/ring the bell loud enough to be heard and if nobody is home, or nobody answers, let yourself in, announce yourself loudly once inside and once confirmed that nobody is home proceed with the "Maintenance Check"?

In looking at the Oridna Municipal Code, I found two relavant sections:  Chapter 10.52 PARKING OF COMMERCIAL VEHICLES and Chapter 3.12 UNIFORM TRANSIENT OCCUPANCY TAX.It looks like the ordinance has defined a tiny house on a trailer as: "Oversize recreational vehicle" means vehicle, other than an automobile, which is self-propelled, motorized, and has self-contained living quarters, including a kitchen, bathroom and sleeping areas, and may be used for the transportation of people upon a street or highway, but not including any vehicle designed for travel on stationary rails or tracks.

Austin was not designed to be a big metropolitan city and always discourage this idea.

.* Design kitchen, bath, and trim* List all fixtures, tile, etc.* Now we can price the rest of the job

Have not used them, but they are big on the east coast and confirmed to me that they will do DFE. 

That could save you thousands of dollars, hours, and a headache or at least confirm what you're already thinking.