Hi folks, I hope you don't mind if I jump in with a comment. First of all Debi and Diane, I just want to say that it's SO encouraging to watch your progression through these exercises. It can be easy to be blind to our own progress, so I want you to know that from an outside perspective the improvements you've each made are abundantly evident.

I am learning Copperplate as well and have taken to heart many of the philosophies and techniques from this tutorial. With that said, I AM still learning, so please know that I don't profess to be at anything higher than an intermediate level (when I'm feeling confident, at that!).
Debi, regarding your slant issues I have an idea. I know Salman has ideas he's touched on for slant problems as well, like paper position in order to make the right muscle habits. I've found that helped me a LOT and I don't have to rely on the lines as much. However, in your case I've noticed several times in your examples the way you interact with the slant lines: your slant often becomes better in conjunction to proximity of the line, unfortunately, your spacing changes. I don't think the spacing is as much of an issue lately, but it used to be (in my estimations) that you would often crowd yourself in order to accommodate the line; as if it were a hard stop, or a period, that you really wanted to fit your sentence into. In other words you sometimes start compressing your letters when you're coming up on a slant line. Have you tried using a lighter slant line in your guidelines? Maybe just 30% or so to see if that affects any unconscious habits you have. This is a purely visual change, but we do make adjustments in our everyday writing in order to accommodate the space that we "see" that we have. Maybe it will be easier to use as the intermittent reference it should be, rather than the law of the letters immediately adjacent to it. Does that make sense? I can try explaining another way if you're interested. At any rate, if you feel I'm speaking out of turn please let me know and disregard this advice, or if you just don't think it applies to your situation. Again, I really value watching the progress and learning process of other people on the same journey I am, so this idea is intended with utmost respect.
Happy Practicing,
Kristin