Thanks a lot for putting so much thought into this. You have pretty much laid out all the steps for us! I am not looking to make any money of this, so that's not an issue.
Yes, that seems to be the biggest challenge for this right now! I have been reading quotes since a long time, so I have a good collection to start with.
Yes, there are websites doing similar things(I frequently read quotes on imdb and Quora), but I miss an app when I am alone and travelling. I also usually want to filter quotes (e.g. quotes from FRIENDS when I want to read something funny etc.)
Only a collection/series of quotes for searched Tv series/movie for now! I agree that a community where people can talk about the quotes or like them sounds interesting.