Watching lolcows is basically like watching a stream online, with roughly the same amount of interactivity. You just observe, maybe you get noticed by whatever is entertaining you (even if you look pathetic if you try desperately for them to notice you), and you chat with the people watching it with you. Making threads is a different story, but that's still not a hobby, it's just something you do to distract yourself.
In that regard, calling watching lolcows a "hobby" is like calling watching a stream a "hobby." You're not really doing anything nor are you improving a skill, you're just amusing yourself. That's not a bad thing, but it's still not a hobby. You also never "become" a lolcow the same way you don't magically transform into whatever the stream you're watching is about. The only way that happens is if you already had a predisposition going in.
Anyway, if you want to post about your ex-friends, there are personal lolcow threads which have much lower standards and encourage more anonymity. If you don't care about yourself possibly getting linked to the individuals they're on, you can post a thread in the prospering ground (and nowhere else unless you really want it to get railed) and making sure you archive and provide photos of anything that's relevant. If it's good enough, a mod will move it into the public forums for you. Note that the impetus is on you. If you post just a few links and sentences, nobody's going to do the leg work for you. People will only help if you demonstrate it's something worth pursuing.