I have Omnifocus 3 Pro so I’m not sure if all of these options exist for you, but I would create a perspective with these rules. If you want only tasks that aren’t completed I would also add an Availability rule.
Great article!! It was very enjoyable to read as I’ve been seeing if switching back to Omnifocus from Things is workable. This means slightly re-thinking how I do things and some of your workflows were great inspiration. I also found your Drafts 5 to Omnifocus article SUPER helpful last night for quickly copying a list from a text message and turn it into a project in Omnifocus with tasks