I'm reading the leg movements a little easier now, but the scissoring effect is still there. I'd really like to see what happens when you do the foot work.
So if you look at the example animations in the tutorial you'll see that the artist is careful to move the feet similar distances when they're on the ground. I haven't run the numbers, but I'd be willing to bet they're close to pixel perfect, if not exact.
And if you're reading the Animator's Survival Kit, you'll be learning a lot about key frames. If you want to think about things that way, your keys here could be the extremes of movement: foot on the floor extended fully forwards, foot on floor extended backwards, opposite foot on floor extended fully forwards, opposite foot on floor extended backwards. Similar to the 4 frame animation in the image above. Now you can choose how many frames go between each key, but space them evenly between the keys. This should automatically space the foot positions evenly. As per the tutorial above, you probably won't need many extra frames.
There is a bit of a conflict here as this tutorial shows the character as always grounded, but IIRC the Animator's Survival Kit shows a lot of air time in its run cycles. It's up to you which direction you want to go in of course, but an air frame or two might help to sell the idea of running and give my eyes even more of a chance to separate the two leg movements.