@nt1 : Sup, yo? Welcome to the forum! To answer your questions above:
To engage, just jump in and speak your mind. Start a thread, post in an existing discussion, whatever. We don't have an in-club or hive mind; it;s an eclectic crew here and half of us don't even like the other half. Don't be shy.
Regaarding 9/11 themed discussions: baby, you've come to the right place. No riddles, just a small army of critical thinking engineers and a lot of takes on the subject that you haven't run across on twitter. This used to be the battleground for those with various conspiracy theories that their proponents thought would never be broken.
Our search function is down forum wide, but the 9/11 discussions are in Conspiracies. Hop in and start yapping, a lot of forumites will guide you to the appropriate thread if necessary.
Most important- read the rules. Theres only about a dozen, but they will keep things productive and prevent running afoul and getting actioned and stuff.
Jump in and enjoy! But seriously, start proofreading. In a highly technical discussion "oh hey man that was another typo LOL" is going to be met with mockery and ridicule, and rightly so.
Go get 'em, tiger.