Imo, beach/sands/rock/ocean are more visual and stick more than just 'shore'. 

To answer your question directly, my top skills are project management and risk analysis, process improvement, and data analysis/visualization of marketing and business efforts. 

Focus more on what provides the best return on investment during a rehab.Having the essential systems (Foundation, Roof, HVAC...) maintained and in great conditions is more important than the visual appeal of the property.

I am having trouble visualizing this.

Before payout of each phase, get a visual inspection confirming the work was done to your satisfaction.

I got to 100% agree with @Jim Pfeifer it really comes down to how passive you want it to be, and you'll need to have realistic expectations about the returns for that level of passive-ness. 

Happy to share what I use for estimating rehab costs - there isn't a fool proof way to do it but it comes pretty close considering you'll want updated pricing for line-items regularly verse having to do a bunch a work to research recent prices every single time for every single property.Always your best bet is to create a scope of work - as mentioned above, a list of all the obvious items that need attention that you can visually see or know from an inspection report.

Help everyone to visualize it. 

Detailed house plan with 3d visualization.2.

Visually, they're nearly identical but actual ladybugs do not tend to infest structures, while asian ladybeetles are well known for doing so.