Sounds like you have most things covered. Some other point to think about, depending on your budget:
- Pre-provision cables for Foxtel and satellite feeds
- Don't forget to add a power point in the ceiling for your projector
- Ensure your have adequate timber supports to mount your projector at its optimum location
- Definitely add a conduit with draw string to your projector. You may want to add accessories like anamorphic lens attachments etc. in the future
- If you ever want to go 10.2 etc, you may want to pre-provision speaker cables now and leave them dormant.