Yes, you should spend on the Discord chat only the a reasonable quantity of time. To sacrifice your life on a chat just to get a few coins more is silly, since it is much more convenient to buy them on the exchange while they are so cheap.
Yes, you are right but there is nothing wrong on chatting in Discord group since through this, members could interact with each other and build a better community. We are promoting Proof of Community, anyway.
This is true as long as you do it out of sincere pleasure in being part of the community. But I guess some stay theere all their time just to rank up for the airdrop, and after that they've spend there 100 hours they will gain more coins, for a total increased value of perhaps 5$.
No, not really. That's just a percentage. Please don't forget that there is also holder rewards. If you cannot interact in Discord, then sign up in the airdrop, buy f0me and hold it until the end of the period. That's still an airdrop.