Reminders are different in that they will actively remind you, even if you don’t open the app window, e.g. by a Windows notification or sending an email.
I understand some of your frustration, but I think much of this is caused by not using the app as it is intended. Note that I’m not saying “you’re doing it wrong”, but I’m saying that the app assumes a certain way of using it, that is based on the GTD methodology, and if you use it differently, you will have a hard time.
For instance you say that you want to sort the Focus view. But actually the Focus view should only contain very few items so that you normally don’t need to sort them. I only sort them manually at the start of the day, in the order I want to tackle them.
As a rule of thumb, the Focus view should have 7-10 icons, e.g. chosen using the “1-3-5 rule” (1 big, 3 medium, 5 small) or the “2-8 rule” (2 that contribute directly to your goals, 8 other).
If there are too many items in your Focus view, reschedule them for a later day (you can postpone by one day simply by dragging to the “Scheduled” folder, and removing the star).
Note that not all of your tasks must have dates from the beginning. You set the scheduled dates often only during the daily/monthly reviews. The “due date” is only for those tasks that have a real deadline, so that they don’t slip through when you do the daily/monthly review.
During a review, you will go through all your projects and take care that they make progress. You will also go through your “Next” actions an check if any of them should get focus or be scheduled for the coming week/month. You go through your “Waiting” list and check that all of these make progress. And if you’re not overloaded already, you look into your Someday/Maybe list (no task in this list should have a date) for tasks that should be promoted to “Next”. During a review, you can also filter for tasks with due date < 7 days and “Prio A” tags (I made a tag for these) or other tags that are important for your goals, so that you don’t miss these.
Another thing: Use the “Areas”. By filtering on one area, you will automatically reduce the number of tasks and see only those which are relevant to the area you’re currently in (like “Private” or “Work” or “Learning”). After filtering through the areas, contexts and other tags, your lists will be usually so small that you don’t need sorting.
I hope this eplains a little bit why the author and many users of Everdo don’t feel that sorting by due date (or sorting in general) is important for them, even though I agree that it can be useful sometimes and it would be nice to have it.
Of course, it all also depends on the type of tasks you’re doing. Some people have tasks which need to be done at a certain date and time, and other people are more free in when they execute their tasks, as long as in the end everything gets done. The latter have often troubles prioritizing and this is where Everdo really helps. For the former, maybe Everdo is not the ideal choice.