[–] beetusvoater 0 points 4 points 4 points (+4|-0) ago (edited ago)
For "easy editing":
Avidemux, FFMPEG etc.,
Blender for heavier things.
Standard advice for torrent is probably transmission-gtk.
But I like transmission-daemon + transgui. By installing them both, you have a client - server relationship established on your machine. You can autostart your daemon without eating resources with a front-end and remote control it (e.g. from another device in your LAN).
Edit: For downloader from OCH in general take a look at Jdownloader2
[–] BlankBruno 0 points 4 points 4 points (+4|-0) ago
Welcome to Linux (and Ubuntu)!
Personally, I have used Transmission as my torrent client for years, starting with it on BeOS and continuing to use it when I switched to Linux. For a long time, I used Thunderbird for a Usenet client, but have recently switched to Pan Newsreader. I can't point to a feature or features in Pan and say, "This is why I prefer it"; for me it's subjective and just "feels" better. As for video work, I have tinkered a small amount using OpenShot, but definitely nothing serious, and I have little to no experience with other similar apps to compare it to.
One app that I would recommend that doesn't fit the categories you've listed is Clementine, an audio player app. I have tried several over the years, and this is my current favorite for ease of use, features, and eye candy. Just my unsolicited personal opinion.
Hope you find my opinions/experiences a bit helpful.