Wasn’t clear from your post if grounding the outlets/protecting with GFCI was part of that bid...

Smokers are not a protected class.

If he tries pushing back, I would go to an attorney and let him know you're serious.In the future, you should have some rules laid down for roommates to ensure their peace is protected and to give them tools to work things out when a particular roommate gets out of line.

I have a few like that.Definitely for asset protection use an LLC for the asset and ensure with your lawyer that the LLC isn't regarded as a pass through entity to your personal name. 

I like to protect myself as much as possible. 

Agents can really help grease the skids and protect the buyer from all kinds of things that can come up.

But in my opinion, you don't need an LLC to do a deal together with a partner (unless you are looking for asset protection). 

If I were to get an easement would I be protecting myself and my investment?

If you're receiving a thing of value for your services, and those services require licensing to protect the public, you're likely practicing that field once you get paid for the clients. 

So i would want to protect his money like it was my own.