Kitchen, creating a separate entrance, and reconfigure the bathroom.

I would focus on things that buyers want like open floor plans, updated kitchen and baths, etc.  

We had a tenant that took us to court for unlawful entry she was awarded damages like 3 times the rent, we knocked,announced maintenance when we went in,  we had a water leak under her kitchen sink, she was a day sleeper, and a cop.

Also you said you're pretty handy so if you find a place with an outdated kitchen/bathroom you could DIY most of it to renovate it cheaply and raise rents that way.

Walk through the dining room into the brand new kitchen featuring all new white shaker cabinets, quartz counters, SS appliances, tile backsplash and a large island.

TNRE redid 1/2 the roof, new paint, water heater, kitchen, bathrooms, flooring etc.

(For some reason they think a kitchen remodel is the better investment...)

Not having any functioning showers, toilets, kitchen sink, etc could easily be interpreted as not being habitable.

I think granite and backsplash elevates the kitchen and makes space more desirable.

I have done a few flips but this is my first kitchen gut.