I think it's easier to comment a pull request. Feel free to send one when you have something ready.
Just make sure that it builds and it is rebased on top of the master branch.

You can also contact us on Hipchat in the Hibernate OGM room, if you have some generic questions: https://hibernate.hipchat.com/rooms/show/1238632

The JIRA works as well.

I have started looking at the code, and found it doesn't support db.collection.find()

There is not a specific reason, our resources are limited and we try to focus on the things the we think have higher priority also nobody asked for it so far.
If one uses Hibernate OGM. the most common scenario is that he wants to get a specific Entity and therefore we usually interrogate a specific collection.

Feel free to open a JIRA for it and send a separate PR if you also want to