My greatest worry would be that he is trying to set you up to gain access where he shouldn't have any. It could be that he is a child-porn addict and wants a place to hide his porn server such that the cops would track it to you, whence he could deny everything while everyone laughs at your pitiful excuse. "I mean, seriously, the guy is claiming WiFi gives
me the pudding poops! Can you believe that child abusing prick?"
No way on this planet I would
ever cooperate with him. I smell a big, fat rat!
Find a buddy (or one of these guys) to help you lock down your network good and tight! Also, have a solid look through all your digital bits and make sure nothing is there that shouldn't be. Someone who knows that much about tracking WiFi (and actually takes the time to do it) likely knows how to hack in and manipulate. Place this guy at the top of your "don't trust him for nothin'" list and keep him there.
Also, rename your network. Call it something distracting like "Office WiFi" or "Chevron Wireless" or "Granny's Gateway".
Finally, contact the Fraud Prevention arm of your local police department and ask them about your city's laws regarding network tracking and interference. He may not be doing anything illegal, but it wouldn't hurt to have something on file in case he is. Protect yourself!
I forget where or when it happened, but I recall a story from maybe five years ago where a guy in (Michigan?) was arrested for hosting a child-porn server. Naturally, he denied everything, even though his PC was loaded with the stuff. He wasn't cleared for months until the investigation turned up the fact that someone had hacked into his computer and installed a web server and the nasty stuff. He was
legally vindicated, but his reputation was shot! Moral of the story: Don't be that guy!
At the other end of the spectrum, he might actually have a genuine problem (if only psychological) and is trying to find a peaceful solution. In that case, there are four options:
1) You use his stuff and suffer with crappy internet performance
2) You move out and let the next tenant deal with him
3) He learns to deal with an issue which, in the city, will
never go away
4) He moves to the country
I vote for number 3. Sorry, but this is the 21st century. In the city, WiFi is
everywhere! The only genuinely viable option is for him to move to a place where his nearest neighbor is at least a hundred yards away, and where the looming, ominous mountains prevent
any wireless signal (including TV and radio) from reaching his bowel.
If number 3 is out of the question, then pick number 2. Honestly, you just don't want neighbors like that, and he isn't going anywhere.