Favourite kind channels : podcasts and reviews about games, theories, culture, also comedy videos, musics.
Following multiple video genre channels => Yes ! I follow them because I like what the creator makes and... I like the creator too. I don't follow everything about them, but there is one guy where I follow everything (the so called French AVGN) because he keeps me interested! I don't like all the things Doug Walker creates, for example. But I really likes his Nostalgia Critic channel.
Catch phrases have some importance, yes. But I found some videos where there isn't a catch phrase, and it is still good. For me, it's just a matter if you want your public to remember you more easily or not. It gives something to the spectator, like the fact that he's waiting for the little catch phrase, and the content only really begins/ends when he says it, or something.
I read a lot of youtube comments. I must say I'm enjoying when there is a useless debate, but I think I'm just weird. Never comment, though, Youtube is THE place where saying "potato" can begin a flame war.
Adapting youtube to tapastic is quite an exercize. It is strange, since the media isn't the same, and you don't really talk, you only write. Most creators don't use their voices, so it is harder to play with your voice tone in a sentence. (smileys exist but it is better sometimes to not use them)
The most of time, this is what I see :
- regular content
- speak or type according to the character you've created or if ti is you, it should resemble to yourself.
- very regular content
- being close to your fanbase : organize contests, tell when there is a problem, make a teaser, or just say how much you like handckerchief to your fanbase on twitter.
- regular content yes yes yes.
The only thing very different from youtube creators and webcomic creators is every creators of channels I follow are invited by conventions and webcomics creators aren't, but a lot of them get a table. So it's important to say to everyone when you go to a convention too!
But those things are already applied to webcomics. So the only difference is the video have moving images with sounds, while webcomics don't. So, less people interested, because you can't leave a comic on the side while you're working, you have to scroll down.
I don't know if I missed the point here... 
