- How long does it take you to write an episode? (in weeks, total hours, however you think makes sense)
Depends of your personal time and how much directing and branching you have to do.
For my first story, I can write an entire episode in one afternoon, if I already have the BG and overlays. Adding to that afternoon, I have the hours I spend looking or editing BG, the directing so I would say 25-30h.
- How many episodes do your story/stories have?
My first in Ink has 7 episodes and it’s on going.
My reviewers know how much of a cheater I’m because I already have 28 episodes lined up 
The second one is a contest entry and has 3 episodes, other 6 planned but I’ve only written a third of the 4th episode.
- How often should someone release a new episode, ideally?
It depends on your personal time and how much you have ready. For my first story, as I’m comfortable I upload weekly or once a fortnight.
For my second story, I started writing the fourth episode, it’s a contest entry too. But in this case, I’m taking my time with that one as I have much on my plate now…