I think the real mistake is one of: 1. I'm gonna use NoSQL because I've heard its really cool. 2. I'm not going to use SQL because its hard for me to write quer

I think the real mistake is one of: 1. I'm gonna use NoSQL because I've heard its really cool. 2. I'm not going to use SQL because its hard for me to write queries and change stuff on the fly. If either of those are true (gotta be honest with yourself when deciding) then STOP. You have to think about the best tool for the job overall - sometimes that will be NoSQL, sometimes it will be an RDBMS. If you can't decide which of the two, then Postgres with its JSON support is IMO the best starting point.