No one bothered fixing the gutters or cleaning the mud out of the drainage culvert, which turned the basement into a desert.

In other words, what are the best ways I can legally use to make the storage unit a profitable add-on rather than an undesirable burden?

Here in the Great State of Texas the tax rate in new neighborhoods will bring you to your knees at just over 3%, including the MUD tax.

I'm simply stating, in a red hot sellers market, the majority of the inventory will be undesirable and it's up to you to educate yourself and cherry pick based on your individual goals.  

Thanks for mudding through it all!

In my ad for the rental, I set some guidelines that should help weed out some undesirable tenants.  

Prices in Fresno for all but the most undesirable neighborhoods are getting too high to cash flow for sfr's but there are still  smaller apartment complexes in B and C neighborhoods  that may work for you. 

However, there are a lot of undesirable areas here.

He was supposed to also finish all mudding, hang two doors and install drop ceiling but he stopped showing up.

I am now a grumpy old landlady who can't seem to keep up with this ever growing pool of undesirable tenants who know too much!