I'm with you on the final fight. I know some people didn't like how it went, but I pretty much agree with your sentiments. As for the dev cycle, I'm fairly certain it's 24 months; DA2 was 18, or thereabouts. It was discernibly shorter, but how much that factored in I'm not sure. Not that I'm trying to excuse them either, of course.
I can also see Cassandra being a party member in 3.