Ask questions, but unless you have firsthand experience/knowledge, limit your direction unless you are willing to accept responsibility for the results.In theory, a duly licensed, professional real estate company will afford greater protection/insulation than a non-licensed person, and make reasonable and appropriate decisions concerning your investment.

If I were to keep the upper floor residential is there any way for me to insulate well enough to prevent noise (and smells) from circulating between floors?

Our Company is insulated from a negative RE economy and actually accelerates profit inversely as the market declines.

In a house I just bought, 1 unit has a small 10x11 living room that currently has no insulation in the walls or ceiling.

Newly redone and well insulated/new windows for lower energy cost.

I have a few properties with water heaters that are in relatively uninsulated spaces (utility rooms, garage, crawlspace, etc) and I want to insulate them with a "jacket".  

Poor insulated homes will keep the heater running longer too.

I got a new Anderson insulated window for $75, and just had to make the opening a tad larger to accommodate it.

If there is only paneling in the entire house, nothing underneath it is worth it to do so you can beef up insulation and fix wiring. 

I'm pretty sure my bonus idea when the time comes to renew the lease is to offer adding insulation in the attic because I remember when we used to live at the house it would get really hot upstairs in the summer time, especially in the master bedroom because it's right above the garage.