On the flip side, in most mobile homes the interior walls are not load bearing but instead decorative, and you may have greater latitude to move those around to meet modern floor plans (but consult HUD before you do this).

House is the nicest in neighborhood (4 bed, 3 bath, hand scraped dark wood floors on entire downstairs, white modern kitchen, greenbelt corner lot), builder downgraded after we entered neighborhood and started building 1800 sqft 1 stories with minimal upgrades, no stone etc.

There is far more accurate science and data associated with FB ads and PPC.You don't need anything other than PPC and Fbads, and SEO.

Maybe there's something to this voodoo science I'm doing

However the aesthetics of modular houses are more modern (sell easier) and the turn around time reduces carrying costs substantially.

It's just a modern term for having roommates (does not need to be in a fixer property). 

When reading modern books that mention technology, it's always best to consider the concept, rather than the actual software.

The floors need to be replaced and other cosmetic renovations are getting planned with contractors to make it much more modern and appealing.One of the issues I cant stop thinking about is the damn heating system.

These people are human and there’s no exact science to pricing a house.

Only you can answer that question, but like you said, it's not rocket science.