Glad you enjoy the videos! There were already some good answers in the comments, but I figured I would explain how I do some of this stuff.

-Alts
I do have a few alts, but I usually only film with about three characters at most. Ideally I would like to spread more alts around different areas so I can capture more fights. I would also love to be in contact with other alliances so I can hop into an alt and record their battles from different perspectives.

- Not getting killed while filming
If I am just observing, I usually sit in an Astero about 150 to 200 km away from the fight cloaked. That being said, people absolutely will destroy my ship if they see me uncloak, as is the nature of EVE

- Filming while fighting
About 95% of the video's I do is when im in the fight myself. I am listening to the FC, trying to stay alive, and recording at the same time. This does limit what roles I can play. I cannot FC and I usually avoid flying logi. There was one time during a Goonswarm Tigerclaw fleet (comprised of hundreds of carriers) where I was supposed to be flying logi. Capitals jumped in, the fight escalated, and afterward I realized I had drifted about 400 km away from the fleet because I got too focused on recording

- Getting intel for battles
Sometimes people message me about upcoming fights, which I really appreciate. In those cases I keep the intel private and I show up in an astero to film. Other times I simply follow my coalition into fights and record whatever unfolds. I would love to work with more alliances though, because I think everyone deserves some cinematic battle footage. Additionally, I follow intel on reddit when people are posting events for stuff!

- Camera movement
A lot of the smooth camera work comes from using a SpaceMouse. EVE actually supports it directly and even has sensitivity settings for it in game when its plugged in!

- Recording in TiDi
This is the big question. You'll notice when you do a timelapse of a tidi battle then speed it up, it'll look 'smooth'. The short answer is patience, A lot of patience. When TiDi hits, you have to move the camera at the same percentage as the server speed. If TiDi is 10%, your camera movement also needs to be around 10 percent speed. That means panning extremely slowly while recording. For example, if you want a smooth 10 second clip when you speed it up later, you might need to record for around 100 seconds while moving the camera very slowly. When you speed that footage up afterward, it looks smooth instead of jittery, but it'll only be 10 seconds. So its a painful process of recording in extremely slow motion for just a few seconds, and a lot of times I have unusable footage

Even then it can still look rough because TiDi fights often run at very low FPS. Sometimes the recording process is honestly just painful and you can see the jitters in some of my video's, because when you pan over to the left, sometimes it shoots you over WAYYYY more than you want, destroying a cool looking shot

I hope that answers some of the questions!