The regulatory angle makes the most sense given the scrutiny they're under from regulators, courts, the FTC consent orders, etc. Also entirely possible that the product manager building the project was able to pitch the fediverse because it was the hot trendy thing (NFTs, metaverse, ai, web 3, decentral etc.)
Given their history of buying WhatsApp and Instagram? Those aren't examples of EEE those are examples of anti-competitive corporate buyouts that should be illegal but aren't. Facebook does not have a history of EEE, and continue to be a large open source contributor, maintaining multiple open source libraries, frameworks, and protocols.
Because you can just block their instance.
They're scraping and selling your data regardless, this doesn't change anything.
Sounds like a lot more potential moderators.
I dunno probably the same way that half of Reddit posts are Twitter links. It will be fine. You can stay talking to your nerdy friends in the nerdy communities.
Threads came out of New Product Experimentation (NPE), Meta's (now defunct) experimentation division that produced tons of different experimental apps to see what would stick, or in this case, to have a card to play if a rival social media network were to suddenly implode for some reason. Was it developed in good faith in regards to Twitter or creating a healthy competitive business landscape? No. Was it developed in good faith in regards to the fediverse? Yeah, they're not gunning after the dozens of Mastodon users.
Until someone can actually state how federation with Meta would harm the fediverse, I'm for it. That EEE blog post that everyone keeps circulating does not do that. Its a quite frankly dumb take from someone who loved a protocol so much they didn't realize that users didn't. XMPP never had that many users, Google Talk did. The lesson to learn from that story is not that Google killed XMPP it's that a protocol's openness does not matter compared to user experience. It's awesome if you can have both, but if push comes to shove, and the protocol can't keep up, then the better UX will always win out, even if it's closed.
No, I wouldn't add them or interact with them.
I trust that they will do what they say want to do, which is to try and get a lot of users and make money advertising to them.
Now, I've answered 10 of your questions and I'm still waiting to hear what the problem with federating with them is that's not just someone blindly regurgitating that same blog post, or making vague accusations that they're so intrinsically evil we'll be cursed if we look at them too long.