Wow! 17 is a good CSI score for someone who has just stumbled across the indicator. Your name deserves the curator part in it.
Tribes are just a word for communities with their own Scot-token which is that thing on Steem-Engine. It's a side chain product and really neat, especially for thinking about what is possible. It is similar to the communities and SMTs that will be introduced in Q1 next year and actually part of Steem. I recommend starting with Steem Leo as they are focused on crypto, investing and business which looks like your kind of thing. They even have their own Steem-engine exchange.

New Steem is just the change in the consensus (and lack of one) since the hard fork that changed curation % and gave free downvotes. It's the reason you noticed your posts are earning more. The vast majority of votes no longer just go to bid bot users. Some people don't like this or think the changes are going too far. Since I don't see Steem in the top 30 blockchains, I disagree and think Steem needs to regain its status.