Having done a lot of web development, my thoughts:
All the different frameworks are essentially different flavors of the same model, so if you want to use one, use one that specifically solves problems you have. They're all just tools to help you make the website/app you want. Design your application, figure out what functionality you want and need, then find frameworks that assist with that model, not the other way around.
Not to come down harsh on you, but the impression you give is that you're looking at all these cool technologies and trying to figure out how to fit them into a project, when that's the opposite approach you should be taking.
node.js has its pros and cons, and it's going to depend on the project, it's not always the best choice depending on the actual application. Its real benefit is in using the same language front and back, which if that's a huge benefit tends to mean you're hiring subpar developers or have other organizational issues(which, a lot of places do both, so that may well be the case and you roll with it anyways). Cause it's certainly not the best performing server, but does have a lot of support.
MongoDB, and this strays far into my personal opinion.. does not really have a legitimate use case. It has a lot of cool features, but it's architecture lacks firm fundamentals. It wasn't designed with a scientific basis in mind, and more as a collection of cool shit in one place.
There's much better solutions to the same problems essentially, such as Riak, Cassanda, DynamoDB, depending on your needs in the CAP spectrum.