At the top it says "Vel from my previous VN is not included", so my guess is that Vel won't actually appear, though hopefully there'll be a few references to it. the VN's seem to be happening in around the same time zone, if you look at the clues carefully enough.
And I think they update the game when they have a "lewd the reaper" scene done, so I don't think they have a set update schedule.
Hope this helped!