I spend my days working as an Engineering Technician in NW Portland and my nights and weekends renovating my first real estate investment, a 1930 cottage. 

If I'm bringing in a contractor to solve a problem -- need an engineering solution, need to reroute a plumbing line, need to fix a foundation issue, need a kitchen layout along with the cabinet installation, etc. -- then most certainly those are situations where you want to consult with with contractors 1-on-1 to determine not just how much it will cost, but what specifically should be done.But, situations where I want/need a contractor to solve a problem are less common than situations where I already have a specific scope of work, and I'm just hiring the contractor to carry out that scope of work.  

Buy or inherit and hold all their lives while working the properties for income.I've seen teachers, firemen, software engineers and all sorts of people utilize both strategies successfully.

With that, a roof top lease brings many more questions than can be addressed in a forum, access, who has access such as engineer, certified tower maintenance techs, roof maintenance, insurance and liability, loss and recovery requirements........ and this lease will effect market value, consider the liabilities and contingent liabilities of maintenance and access, not just the surface of the roof but the structure below the deck.

I graduated with B.S in Chemical Engineering from University of Houston- Cullen College of Engineering.

I work for an engineering firm in Indiana and do that type of work.  

Unit has brand new Berber carpet from previous owner but am thinking of installing either hard wood, engineered wood or porcelain tile.Anyone have a good floor installer or contractor who could do the work? 

I understand this would be a long process of permits, a structural engineer evaluating the house and drafting blue prints, etc...Question 2. 

What needs to be done- land fill, engineering, etc.? 

You will probably need permits possibly an engineer.