Like others have asked, we’re missinga lot of details on what you mean by tag system. What’s the origin of a tag? Just a text field with free text (maybe assuming comma separation)? Are available tags defined per instance? Per community? Globally? And consequently, who maintains the list? One tag or many per post? Per comment?

Can I tag other peoples post or comment?

You seem to have a reasonably concrete idea, but unfortunately I don’t yet, so it’s hard to answer.

There’s a button in three to right where you can change the sort order (next to the 3 dots submenu). This applies to comments and posts.

Also having this issue. When I place my finger on the screen to scroll, it initially kinda “stick” a bit as if it wanted to act like a tap, not a swipe. But then it does start the scroll. And yes, the scrolling action is hard to describe, but certainly not smooth. No other app feels like this.

I’m on a OnePlus 6.