Anyone know any decent video tutorials for getting down the fundamentals of proportion and scale and outlining and such? I've been looking at artist's work I like (Ueda, Tony Moore, etc)
That seems like a strange solution. You're looking for someone else to explain what you should be able to see with your own two eyes.
Okay, that probably sounded kind of dick-ish. But look, you can get a textbook definition of how proportion and scale work off of wikipedia. Actually acquiring an understanding of it? You have to draw it yourself. Photographs work, of course, as does drawing whatever physical object is in front of you. Eventually combine the textbook explanation with your practical application, and you should be able to understand the hows and whys of drawing.
I've been looking at artist's work I like (Ueda, Tony Moore, etc) and trying to mimic what I see there, but I'm still limited by the poses and characters and proportions they've chosen.
You're not limited. You just have to draw what the other artist didn't. It's simple mathematics, dude -- calculating the third point of a triangle. You've got one drawing from this angle, another drawing at that angle, and all you have to do is figure out what the third angle is.
It's not working as well as I hoped in terms of getting me to the point where I can commit out any old scene in my head to paper/photoshop.
If your drawing ritual is as simple as that, then you probably will fail at committing a scene from your head to a drawing. Get some reference photos, do some rough sketches. Skill and ability are important, but creating a drawing plan is just as, if not more necessary.