Videos come with hashtags which are text and thus searchable, then the algorithm recommends similar videos or other with the same keywords that are related.

A lot of information is better in a visual format than text: tourism guides and art for example.

Sure but you must know the forums and they have way less user base than TT where you have all content with a single search engine.

Yes there are a lot, note that they have a different feed for chinese citizens where there are probably way less.