That makes perfect sense and is the recommended way to go. Run up steps really don't give you much added D and the consistency goes down so much that in many cases it is not worth the risk. it is better to be in the fairway. 250' stand still is good for anyone so it is great for a woman so congratulations on getting close to it. It means that you do have the potential to go way farther than 300' already. Coordination is a difficult thing to master especially, when you should reach back so much. It is not a motion that people usually do so you start out with the experience of a baby like all of us have had to. Field practice and adding one step at a time helps. One step run up first then two and so forth until you nail it. There is no point in running with more steps than, what gives you the best distance. And you should be able to not lose much elsewhere while adding each step. It doesn't help to lose form. I've progressed slowly, because i can't swing my hips around at full run up speed unless i do the unhealthy way Markus Källström does. I don't want to go there even though it adds speed, because i'm injured enough and people have ruined their hips using that form. And Markus is super beefy in the legs and hip area to handle the stress. I'm not. I think that my hip issues are at least partly related to a spinal injury and subconscious relief. The way Markus throws forces the hips to turn so it is tempting to say the least. The torso turns way faster with that method.
The hyzers sound like wrist rolling counterclockwise late in the throw. Tightening the wrist area while pinching should help or you may need to stiffen the wrist a little earlier. Practice will show, which timing eliminates the hyzers. Leaning forward does not cause hyzers unless you also tilt the hips or the shoulders to the left.
Fred Flintsone happy feet are a common problem. Try an x step with exaggeratedly slow first step and a veeeeeryyy sloooow x step followed by a brisk plant step. After that try to make the x step progressively faster while still keeping the first step stupid slow to see, which speed of the x step works best. Then keeping that x step speed try to add speed in small increments to the first step to find the best speed for the first step. Once you've nailed the speed for the first step try to keep it the same and see if increasing the x step speed helps, because things have changed with the faster first step. Once you get the best D it is, what you should use. Only then should you try adding the first run up step. Happy feet gotta go they won't help you.
You should try to make your fingers limp until the right pec position at the least. If you don't get slips, while pinching later, you'll move your arm faster.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.