Collect data on Views and Favs of user, multiply it by Tags_of_post and Favs_of_people_who_have_seen_same_post, magically analyze it and boom we've got recommendation system (which probably also could be payed feature due to computer resources needed?). Maybe also add some AI on top of it, idk.

go to trac

Unless lozer has had a change of heart, we do not plan to ever lock site features behind a paywall. If a feature really would be resource intensive enough that we'd need to charge money for it, it's probably not going to be implemented.

Maybe. A booru site for figures ref content? Moving all the content in this new site, a plus, we can know the artist of the figure.
There's already gelbooru, danbooru, realbooru, AIbooru, yande.re, zerochan, e621, rule 34 etc... one more, why not?
Examples:

Art: gelbooru.com/index.php?page=post&s=view&id=1650479
Figure: gelbooru.com/index.php?page=post&s=view&id=8017664

Art: gelbooru.com/index.php?page=post&s=view&id=3806292
Figure: gelbooru.com/index.php?page=post&s=view&id=7852512

Art: gelbooru.com/index.php?page=post&s=view&id=4701363
Figure: gelbooru.com/index.php?page=post&s=view&id=9714187

The answer to "why not" is that we don't have the resources to moderate it. If you want to start it yourself, the Gelbooru 0.1.x branch is open-source.