I stay away from historical buildings in general for all of the above reasons and more, unless it's a larger scale commercial building with concrete floors and great "bones" that can separate the uses/tenants better.

I always seek and provide concrete, actionable steps to be successful in this business.

I feel the future is much more concrete when you have a definitive goal you have laid out rather than just saying, "Someday I will be worth $1M."

Full renovation with new concrete driveway and new concrete walk out basement.

Not only do most investors spend too much time sitting behind a computer polishing off their fancy excel spreadsheets, they rarely walk properties.

Full renovation with new concrete driveway and new concrete walk out basement.

For people in the Brooklyn area, do you have any cement/concrete professional that you'd recommend? 

The tenant toured my place, said is employed (+i googled) , came across to me as very polished  and came to tour the unit with her mom.

I am unsure as to the foundation of the cottage, but the modular portion appears to have been a poured slab (approx. 5" deep) with concrete block skirting. 

You could sister it and/or dig & pour 24" deep concrete pads in the floor to support additional jackposts.