I guess what I want is a schema-ish database, where I can say "these 5 fields are required and must conform to these rules. Anything else is fair game."
http://thebuild.com/blog/2013/07/02/postgresql-as-a-nosql-da...
For that matter, if you use NodeJS, then said API and the backend structure are fairly trivial. I used NodeJS to create an API for queries against MongoDB, and it allowed for me to normalize and check data in said queries against the data. It also allowed me to do programmatic elimination of sensitive portions of data from the front end without much effort at all.
It seems what you really should be creating is an API that your application uses. I'm a proponent of the Data Storage Layer being as dumb as possible. If it weren't for the built in indexing, and common access structures, I'd be more inclined to roll my own. I do think that MongoDB does a nice job of striking a balance between say Couch and MySQL (I intentionally use MySQL here instead of PostgreSQL or MS-SQL). I also think that RethinkDB within a year or so will likely be a better option for many of those thinking about MongoDB.