Happy to help! OmniFocus can export a calendar file, then help the iPad's calendar app to subscribe to that same calendar.
If you sign up for an account on our
Omni Sync Server that'll give you a free spot to store the exported calendar file. (The server will send you an email that helps configure OmniFocus to sync with your account.)
Once your sync is set up, you can enable Calendar Alarms in OmniFocus' settings. Sounds like pretty much what you're looking for. Hope this helps!