I think you have a great plan barnbum and I'll be cheering you all the way. I pretty much learned the way you're planning to. Practiced and practiced ad nauseum until I finally felt I could do it on a real quilt. Actually, I pretty much did one "real" quilt before I practiced so much, and it was awful LOL, so I decided I needed to get more comfortable working on smaller sections at first.
I just started by making loops and meandering and before too long I got confident and added more designs along with those two. Just have some fun with this!! You can do it, and you can do it well. I know you can.
I love the idea of putting them all together into a quilt later on. Wish I'd thought of that. You'll be able to document your progress that way.
And I'm very proud of you for trying this. I really hope you come to enjoy it a lot. You'd be surprised how much bulk you can fit under a small throat once you get some confidence in what you're doing. The machine I started on before I got the Juki has a mere 6½" throat, and not very tall and I was able to get bed sized quilts underneath, half at a time.
Good luck and I can't wait to see your work! :)