David J. has some good points ...If I were in your shoes ...

In your shoes, I would be concerned about cap rares increasing in the future, wiping out your equity.I would look into splitting up the properties between yourself and your sister, then sell your buildings and do a 1031 exchange into another property, commercial, multifamily or residential, whatever you feel comfortable with.So long as you are making money from your investments, is it really that cumbersome to write one more check for your mortgage every month?

I was in your shoes about a year and a half ago.

Other than that, it's easy peasy.I'd use shoe molding to cover the gap.

However, I fully recommend having a call with tax strategist who can showcase the best option for your scenario(ensure they invest in real estate for best outcome).

To learn from those that have been in my shoes.

So do you still think this is not worth it for you to spend what you would spent on a good dinner, a pair of shoes, neither of which will make you or save you $$ in the long run.

Unfortunately it is what it is, and I've been in your shoes before with wanting to do things myself.What I've done for some jobs like that is had a GC I know pull permits for $300-500, then I or a handyman I use that the GC knows and knows he does good work did the repairs and had it inspected.

The first thing I would do in your shoes is to ensure that my personal assets are isolated from my business assets and my business assets are isolated from one another, in order to protect yourself from a suit. 

If you contact a developer / builder of high end homes, and offer to accent some walls in the model to showcase your work, I would think you would end up with lots of work.