If your 5000C has no drag it's because you bought it second hand and a previous owner did bad things to it. Here is a photo of a 5000C and you can clearly see the star drag adjustment.
I think you may be trying to overthink the drag thing here. This is all pretty simple. Hook the line to a door knob and try it. In the don't bust your line on a door knob scenario you won't leave a fly in a fish. All the information you need is in my previous post in a pretty clear (or at least I thought it was) manner. Go back and reread them. hook the line to a door knob and walk backwards. You will understand it perfectly in about 3 seconds.
Here's a newer version of the 5000C, still has a drag.