I noticed that my titanium wedding band left a line on the apron front of one sink with only a light brush across the surface.

Clean the surface good, then  make spot repairs, and finally apply a healthy  elastomeric coating on top.  

And finding something that would also break down hours per unit, like number of hours per 100 square feet of wall surface, etc would be amazing.

An exception would be extensive storm damage that goes beyond the surface and affects multiple areas.The most common repairs performed on roofs include:90-95 percent occur around flashingBlown- Off or loose shinglesPonding water due to insufficient protective measuresPunctures or penetrations relegated to a single areaShingles that are curling upwards may mean there are leaks underneath the surface or that water is getting into parts of a roof where it shouldn’t be going. roofs with curled shingles often need to be replaced within 1-5 years.Complete replacement is typically recommended when:Damage extends below a roof’s surface layerRepairs are becoming increasingly frequentBald spots are showing up where granules( materials that provide added protection to a roof) are missingA roof is more than 20- 25 years old or has undergone too many re-roofs to make re-roofing a safe option againAn existing roof was poorly installed or not installed according to codeRoof replacement doesn’t necessarily mean completely tearing off an existing roof and starting over from scratch.

If the house is just a C-class basic housing type place, you could use surface mounted conduit to rewire.

I wrote a pretty cool script that allows me to surface real estate buying opportunities based on pretty much any characteristic.

Perhaps a dumb question but wouldn't many of these be largely subjective based on variables such as quantity and surface area?

Yes, there may be a success story or two out there but please read between the lines and look beyond the surface. 

I fear that I would mess up the floor level even more by potentially not spreading it even over the entirety of the surface, or am I scaring myself for no reason?

Hi Michael, are you trying to stop water from the surface of patio only?