For [1], I saw in the yesterday update that the web version also can sync secret chats. I don't have my laptop with me (for another month), so I have to check

For [1], I saw in the yesterday update that the web version also can sync secret chats. I don't have my laptop with me (for another month), so I have to check this, but based on the redesigned devices dialog, I can imagine that this is now solved.