Based on your interest in being an ethical person, it seems like this situation could work out very well. It's totally possible to get the place set up so that you rent out a nice, very livable space for a tenant that is less expensive and/or nicer than other options they might have, and you will likely be a considerate landlord, which would make you and your tenants happy and comfortable with the situation.
Being a landlord is not inherently evil, nor is it inherently a complicated and frustrating existence. In fact, the world could probably use a lot more nice, considerate landlords. You could be one of them!
I switched to a mini pc about 1.5 years ago, and it's been working out fine. I'll probably get another one when it's time to move on. One thing I like about my new setup is it's more modular. I have 2 external SSD drives and a USB hub, both of which I can continue using when I swap out the 'main' pc. I have a fancy audio interface hub as well, so I'm not concerned about any lack of enough audio ports on the mini pc.