He does a lot of work for me and is currently using my basement for storage in return for work around the house.Is this a good idea to go through with renting the apartment to him?

It's an entire house, a full basmenet for storage, a yard and a garage.

The $500K SFR rockstar agent isn’t the $500K rockstar self-storage expert.

But I'm wondering if I should up my game and install one of those storage systems, this should rent north of $1800.

I have a few storage tanks and some shipping containers to store equipment.

Does this typically mean I need to buy an extinguisher for each tenant to have in their unit or just in common spaces (stairwell, basement storage, etc)?

it's going to be rented to a non tenant, used for storage.

I recommend archived files be moved to a different storage location, such as burning them to a DVD or zipping them up and placing them in a cloud storage location different than your main folders. 

Even if you can just add a carport that will help-the new owner can throw a shed in the backyard and now there's storage.

Just checking if anyone has any experiences with them whether good or bad or any other device that they can give me regarding this information.Any help will be greatly appreciated!