I think you understand it rather well, Brian.

The reasons that you still feel you do not fully understand may be because of 1) the somewhat interchangeable nature of some of the terms used (not by you in particular, but generally in books and forums), such as 'contrast', 'resolution', 'resolving power', 'acutance', 'micro contrast', 'clarity', 'sharpness', etc., and with 2) human vision not being as straightforward as testing devices used for measuring the above quantities may suggest.

The properties of an image are difficult to qualify. Then throw in human vision, and what you're left with is your feeling of confusion.

But again, your initial description where resolution and acutance (and perhaps overall contrast) together determine a certain perceived sharpness is perfectly workable, in that it enables you to get a feel/measure for the quality of say a print you've made.