Thus, focusing entirely on residential throughout your life by necessity means that you will reach a scale barrier that will be difficult to jump past without additional effort and risk exposure.

Multi-Family is a necessity.

The owner most likely is in an exclusive contract with the agent so including them will be a necessity, but in my opinion you can make a deal with the owner you just have make sure that you factor in comission for the brokerage.

While most people see utilities as a necessity of life, them folks see it as the Government and big Corporations trying to take something away from them.In a mountainous or wilderness areas, 10 miles can be a 45 minute drive, or more.

This is what I do to analyze my deals, but having a good realtor to help you is the best assurance to back your analyzing (since they analyze markets for a living).As far as getting your license I would tell you no, but its not a necessity when you start out.

As he becomes more experienced, like yourself, he can then judge the necessity for a title search.

For an estimate of this size, you absolutely need a second opinion on the necessity of the repairs and you also need comparison pricing. 

STRs are not a necessity but rather a luxury.

I could see the necessity to be on the insurance in case the tenant tries to sue them, but I figured their real estate insurance would cover them.  

Every property management company will provide a breakdown for their services and it just comes down to your goals for the property and quality of life you desire while traveling.Pending on the type of MTR travelers you receive and your space, with MTR you are providing the same things as a STR, but most of the necessities (paper towels, toilet paper, cleaning supplies, etc) are going to be fronted by you, but necessary for you to keep them stocked week by week or month by month (based on the expectations you set up from the beginning).