A stacker is someone involved in the Stacks community, but also someone who is locking their STX to participate in consensus and earn Bitcoin.
Newbies start at stacks101.com, official sites and wallets, read some of the whitepapers, and community content to get a better idea of what Stacks is.
Decentralized autonomous organisations on Stacks. In the future DAOos will make it easy to launch your own DAO with on chain voting.
Stacks token offerings from the past were all SEC approved. And soon the exit report will be filled because Stacks is a decentralized network and not a security.