If you use the popsicle stick method, you want to visually verify that the angles of the stick to the sides of the blade are equal (right angles). If you want to be extra careful, bring something with a right angle corner to each side to touch, to verify that it truly is a right angle.
However, if you have a very fancy blade, it may be side honed in such a way that the angles are not right angles. E.g., the bottom of the blade may have been ground wider than a few mm above it, which some people call a dovetail shape - it makes your edges a little sharper, but is fairly difficult to sharpen right. However, the two angles (on each side) should still be equal.
You also need to confirm that the popsicle stick is not warped. Place it against a flat surface or a straight edge and see.
I personally don't like a blade that is too far offset to one side. It makes it hard to spin, which is already hard for me. I personally find it better to modify the inside of the boot. But it is a very common method, which will eventually make you skate straight.
If I understand correctly what a Footbalance does, it may not correct your problem. It molds to your feet - which is great for many people, creating equal pressure on all parts on the bottom of the foot, and mostly preventing the collapse of your arch. It might be great if your only problem is that the shape and tilt of the bottom of your feet doesn't match the tilt of the top of the footbed. But to correct over-pronation, some people may need extra material under the center of their arch, or under the entire arch. Try adding adhesive tape or foam (athletic tape or moleskin) to your Footbalances, or to any insoles, under the side of the foot which collapses. (For reasons I still can't understand, some people find it helps to add material to the opposite side instead... Try it if the other fails.) Another issue is that it must fit tightly, and not rock around as you move. Another thing to try is moleskin stuck to the inside side of the boot, above or below your ankle, on the side your foot collapses towards.
BTW, are there any parts of the boot below your ankle that feel like there is light pressure or no pressure? You can add tape or foam there too, so that you don't lose control of the boot because nothing prevents it from moving around.
Basically, just keep playing around, until something works. Eventually, something should.