I poked at simple_form a few months ago and also found that it’s way too coupled to ActiveRecord. I started pulling it apart and implementing features that we were missing and we got some cool stuff as a result. At the time, I couldn’t finish it up because we needed autosaving of associated records in place, and that required transactions for all save/update operations, and that wasn’t possible then. Faced with that, I moved it way lower on my priorities list because front-end frameworks like Ember.js and AngularJS are such better fits for Neo4j-powered apps and we had more pressing issues.
Now that we’re using transactions for all save and update actions, I think we could finish up support for this, though it’s still a few notches down on the to-do list. If you or anyone would like to partner up on it, I’m happy to contribute. In the meantime, definitely pursue something like Ember.js. It’ll give you the best most control of your objects in the view.