Sounds like you have the same problem as me - Too many unactioned reminders. You're proposing using the reminders window like another to-do list, but that's not what it's for. We have the "F3 window" for popping out a to-do list view.
The best way to use reminders is to set them for when you need to do the activity. If they come up and you have to defer them, best to change the reminder for the new date and time.
That's a long way of saying I suspect that MLO won't be prioritizing any development of sort functions in the reminder window.
All the best,
Stéphane