@Erin K. it would be in the typical places you would see in a stick home at the time - ceiling tiles, pipe wrapping, insulation, maybe other places.

Did they remove the bottom four feet of drywall in all of the rooms to dry out the studs and insulation or just vacuum up the water?

Which could possibly end up being more during winter due to poor insulation.

However, if you do need to remove it - ie. you were going to put 1-2" of rigid foam insulation over the exterior of the house -  it is one of the asbestos abatements which can safely be done yourself.  

Garages usually aren't well insulated, so you'd have to do that to make it heatable area.

When I had to sell, I ended up eating features that no one but me cared about - 2x6 walls, upgraded insulation, downdraft stoves, etc.

Also be wary of wholesale and fix and flips that may have adverse tax consequences and need to be insulated in their own separate tax person (corporation) to avoid propagating to your other passive activities.

And as I said, maybe I select the tire shop at the lower return vs the bakery because I believe it's insulated from a financial recession and safer money or it's in a better neighborhood or the marketing is lackluster and I believe there's more opportunity than with the bakery.

I was just over last week to look at another landlords property which my carpenter renovated in 2013 - full gut, new kitchen, new bathroom, new windows, new outside door, insulation added to the envelope.  

Short term improving the building envelope through insulation, programmable thermostats might help.As for switching to gas, price it and any rebates you get.