It'd probably be a more organic way to learn about the world of TNH than reading through the Codex; the writers could also sneak in some funny lines in there too.
I don't know. I suppose.
I'd mainly just have it as a way to get love points and make small talk without getting an angry X-Woman coming at me.
You already kind of do learn a bit about the world through dialogue, or at least the current state of affairs through story events. Reading the newspaper on the phone also helps with that.
Normal dialogue so far with the girls during their quests is often reinforcing what era the game is in, though sure more would be good.
Right now Null has been more or less stuck in or around the mansion for a year. If he gets to go to more places in the story I'm sure that will help too
Something happens when a time period ends (day or event where you have answer options). When it ends, my weak laptop starts groaning as if you were sending an old man up the stairs to deliver a bucket of water.
I haven't looked at the code in detail, but I noticed this behavior since 0.8c.
Probably does it's checks and adjustments at those times.