As Groucho said, I don't want to belong to any club that would have me as a member. Here's the thing -- by making it a 'club', and making prospective 'members' pass muster, you're just replicating HR at a big corporation. Friendship isn't so much about matching activities and interests as it is about finding someone whose sense of humor matches yours, or going through the same experience together. No matter how lonel…
back in the long-long ago when i was online dating, the biggest boon it provided was that it gave you a space where you knew that it was okay flirt and that your intentions would not be misunderstood. you never had to guess if it would be a creepy time/place to flirt. you never had to worry about your intentions being misunderstood as "just being friendly". if somebody was on this app/website, they were looking to flirt and if you approached them everybody was clear that you were flirting.
doing something similar with friendship could be great.