Examples: Oil&Gas, Farming, Govt contracts, Cannabis, Export/Import etc. 

I understand that there are different types of investing (wholesaling, flipping etc.) that someone can pursue, and could be a valid reason, but is there anything else that I am missing here?

The first thing you'll need to do is figure out which are validly perfected and existing liens which will need to be dealt with.

Rod's message is valid, but not particularly viable, in my opinion.

Gas & Electric appliances.

The lady quoted me $2400 for 50 gallon gas water heater. 

Biggest problem was the heat situation. current owner was spending $12,000 a year on heat and rents were low. first thing we did was install 4 gas monitor heaters, 3 units already had them, separated the propane tanks and turned off the old undersized oil furnace.

At the federal level on the tax side, there was an IRS PLR recognizing validity of the S-LLC.

I brought my house as a 2 family (2 gas meters, 2 electricity meters, and been paying tax for 2 family since brought in 2003).

Although before moving back to my own house we had an agreement that I would only pay utilities plus some other bills like Netflix, etc, while I was getting out of debt. they are using an  excuse that my girlfriend is at home so everybody got a pay for her/his own room, Although she only use water Gas and electricity Morally I decided to stop counting with my home-equity  because I think it’s a big responsibility and my family is living there too.