I've done a lot of genealogical research into my dad's side of the family (I'm eligible for Italian citizenship through my great-grandparents), and it's been really fun finding out little tidbits about his family. But there's so much I wish I could ask him, as it's all fragmentary and big-picture, and lacks context.
I'm so envious of you that you have a recent, focused video record of your father. My sister has a bunch of old VHS tapes that might have my parents on them, but the tapes may have degraded, and, regardless, they're not recent, and even if the tapes are still functional, they'll be of generally poor quality and resolution (and worse, we were cheap and would record everything in EP mode). Neither of my parents liked having their photos taken, so I don't have a lot to work with there either.
So sorry about your dad, but I'm glad you at least got to get a little closer to him before he passed.