Can I make videos on warframe gameplay? I can't deduce it from the terms, I saw plenty out there though I am still no quite sure.
Yes, you can do videos and nobody will close your channel.
But, if you're asking if you can make videos and monetize them via youtube, this might be kinda different. If you're going to take that road, I suggest you to open a ticket to Warframe support, so you can have official info and a written proof, if the need arises.