While i have never used kbin i have no doubt that it can do everything listed above.
Really the fediverse is a "choose your own interface" kinda place. Do you understand reddit UI best? Use lemmy. Does twitter UI make sense to you? Use mastodon. Do you like both? Use both for different reasons. Either way you can interact with anyone, using anything, anywhere that uses activitypub and anyone, from anywhere, using anything supporting activitypub can interact with you. That is the whole point. Get rid of the silo social media so you never have to lose your social graph again because you moved to a new service they are not on