I definitely see improvement. I agree with Wolph on dry erase board or plain old paper and pencil to practice. Also there is absolutely no shame in premarking! I do it, Karen McTavish does it, many, many award winning quilters to it.
When doing feathers, I find I can only go in one direction. From base of the spine up to the top. I can quilt or draw them in any orientation, vertical, horizontal, diagonal, on a curve, facing left, facing right but I have to always do it from the "bottom" of the spine (even if the feather is upside down and my bottom is at the top when looking at it) and work my way up. So if you find you are the same way, that is fine, just practice it facing different direction
You have it much harder than us LAers because you have such a limited space to work in so you have to teach yourself to quilt based on that limitation. However, a bit of premarking or reference dots on your quilt top you will be able to churn out some beautifully custom done quilts in no time. I think after a year or so with your lavender love, you will be itching to find something with a bigger throat. Seeing as your DH is such a whiz with the vintage machines, you should keep your eye out for one. I know there are vintage LA Singers out there, or even the industrial singers have a bigger throat on them.
I think you are ready to try an actual quilt top. Put one on that isn't so important to you. My first real quilt, I hated the top so didn't care if I ruined it. It turned out really nice, mostly because I didn't care about it so wasn't stressing that the quilting turn out great.