(Also what's the best way to learn the formulas so I can figure out these kind of questions for myself?) Buying an advanced Physics textbook seems too daunting.
As someone who regularly assigns the question you asked as homework (in an advanced physics course, mind you), let me put in a word of advice: don't think of what you're aiming for as "learn[ing] the formulas". In my experience, that mindset (which fits so very well in most high school science classes) is the single most common stumbling block for college-level physics students.
Equations and formulas exist purely in service to concepts. If you can't tell a story about "what's really going on" (qualitatively) without reference to the equations, then (in most cases) you probably shouldn't try to use the equations, either. I see student after student try to solve complicated problems via "equation hunting", where they just dig through their notes or the textbook looking for formulas that have the right variables in them, and then look for ways of combining them to find an answer. (Sometimes their thinking is a step more sophisticated than that, but it's a characteristic pattern.) Students start to become experts in physics once their mental model of the subject transforms from a jumbled pile of independent equations into a network of concepts with equations like little neurons binding them together.
Yes, that's an excellent point. So I guess the follow up question is how to learn the qualitative ideas behind electric fields?
I've got a lot of inventions I've thought of related to static charges, and I'm trying to basically figure out why they wouldn't work. Maybe I can email a couple over to you and you can point me to the right concepts? (email in my profile)
Alas, the trouble is that it's tremendously hard to learn (or teach!) the qualitative ideas without also learning the equations. (The only counterexample to that I've ever seen in physics is Feynman's amazing little book "QED", which isn't at all what you need here.) So I've got nothin' for ya. (And while I do enjoy conversations about this sort of thing, obviously, I can't possibly sustain one with my job these days: I'm already going to regret the time I've spent on this one. But it was fun.)
There's no substitute for actually working through the equations and math, but working with simulations can help drive concepts home. For example, PhET has a virtual capacitor lab (it's a Java applet).
The voltage wouldn't change, but the energy would decrease. The energy stored in a capacitor is a potential energy, which means that the energy depends on the orientation of the capacitor's plates. The decrease in energy is equal to the work required to pull the plates apart.
