I think what you are doing is riding a fine line between legal and illegal and it's not worth it. Even if you are getting free internet, you are essentially becoming a reseller by sharing your internet with various unknown people. How would you even report your income from this. I'm no lawyer or computer genius and I don't even know what I'm talking about most of the time. What I do know is this sounds kinda shady and risky in multiple ways. Go find some other way of making a few bucks that's simpler to wrap your head around. I mean no disrespect by these comments just putting in my two cents. Food for thought.
Nothing illegal or risky on it IMO. In the UK the BT hubs share bandwidth automatically as hotspots.