Yes and yes. :) The problem with the first one is I have to make an individual API call for each comment currently. If you go past 50 comments it starts to get slowwww. For example, I tried to pull back all of @pg's comments... Bad idea. It's like 13,000 of them. Check it:
https://hacker-news.firebaseio.com/v0/user/pg.json?print=pre...
I think I've seen a few archives of HN comments. Maybe grab some of those and only make API calls for newer comments? Also preserve the comments from the API calls?