I like your workout for the following reasons:
1. You start with balance.
2. you use short distances.
3. You add in small amounts of whole stroke.
What I don't see in your post is focal points. I suggest you bring 2-3 focal points to the pool on each day and spend 5 minutes on one before moving to another. Then cycle through the same focal points as your session continues. I would also suggest using the same 2-3 for a while (a couple weeks). Then, after you have the basics down, go back and spend the time to really nail each one. That will take months on each one.
The mistake I made in the beginning is that I changed focal points too often and I am - realizing that I am only now (4ish years later) developing a consistent stroke. For example, I noticed that I have two slightly different balance positions: one has the hip about 1 inch higher than the other. It doesn't sound like much, but that inch higher gives me one less stroke per length and a slightly higher tempo. At the moment it requires a little added effort in core stability, but that is minor compared the added efficiency it offers. This double position happened, I believe, because I changed focal points too often in the early days. I spent a few weeks exploring all the focal points I remembered from my workshop and those I saw here. And while all the ideas (well, most - we all go down a few blind alleys no and again) were great ideas, I couldn't imprint all of them in a year. I realized I am only 37, and on my way to setting world records in the 105+ age group,(according to USMS Swimmer, no records have been recorded for that age yet) I have plenty of time to really imprint each focal point.