Hi Tomsde
Each of us have to make our own decision as to what we do or don't install on our computers. However, I've had For Rent installed since it released and haven't had any issues to date from it, knock on wood, lol.
I simply opted not to use the gameplay. I have sims living in the world in a residential lot and visit the Night Market etc. I just don't play as a tenant or a landlord, though there are those who have done so without issues. That is also a personal decision. I can only say that I wouldn't hesitate to install it. I have used build/buy items in houses from the EP and wouldn't want the missing content.