For adding the 15 grams, you can go either way with that actually. 9 grams at the head or handle, it doesn't really matter. 9 at the head will produce more power, while 9 at the handle will be more manageable.
And you're right about the difference between depolarized and polarized, except that polarized doesn't necessarily straight out give more power. It gives more racket head acceleration. That can essentially equate to more power as power/force is generated from either (or both) increases in mass or velocity/acceleration. I'd prefer to keep it at polarized means more racket head speed (if you know how to use it right). Also, the control problem isn't as big of a factor as I might make it sound. Higher racket head speeds (especially at the tip) can be used to create more spin on the ball, resulting in more control. Your ability to accurately control the racket head at high speeds will surely go down, but as long as you use spin to give you margin it's going to be fine (but don't be too surprised if a few don't go your way, but with the spin it generates you'll get plenty of margin so you won't notice 99% of the times where it happens).
And 10&2 and 11&1 will give still give power/plow through and increased racket head speeds, though I prefer to stick to one side and go all out in that direction. But if you were going to do that, I suggest 10&2 since it doesn't reduce your racket head control as badly but will give you noticeable more momentum in the head. If you go to 11&1 you might as well put a strip of lead across the top of the hoop. I don't personally advocate a bunch of 3-5 inch strips at 12 to polarize a racket, I prefer a long strip that can actually be as long as 15 inches across the top of the hoop so the center of mass won't be raised as much and the racket won't become more difficult to control. Some people prefer it that way, and I'm not saying you shouldn't do it. Try it, it might work for you, but it doesn't work for me.
It all depends on what you need from adding weight. Sometimes it's not as straightforward as wanting more power. You might want more pop, but are want a hint more spin on your shots than a 3&9 setup will give, and are willing to sacrifice a little pop to get there. In that case, yes go for 10&2.
If you want more pop on your serves, I recommend lead at 3&9 unless you might want to get a little added spin and kick on you spin serves as well, then 10&2 might be more appropriate. I've never personally experimented with 10&2 but it should add more spin than a 3&9 setup although you will probably lose a little stability and power (probably not a noticeable loss though unless you add a lot of weight). Personally, a polarized setup messed with my serve the most. Granted the amount of spin and kick I got on slice and kick serves was truly amazing, but it was difficult to really control it and stay as consistent as I liked with it. Occasionally I'd get too much lift and send it long, or too much spin and send it short or into the net (but with a giant explosion off the court). Granted, I didn't stick with the racket and practice with it as much as I should have, which probably would've fixed the problem, but from an immediate racket switch standpoint, it was simply too erratic. Now, for groundstrokes, I don't think I missed a single topspin stroke long or into the net. I easily ripped the ball 2-4 feet over the net and had them all safely drop on or inside the baseline with no problem and had insane amounts of kick on them. My friend could actually consistently pull off drop shots with so much spin they landed next to the net and died on the bounce, if not going back into the net. And he ran me around all over the court using heavy spin to generate sharp angles to both sides of the court. Depolarized setups are great for people that love to use heavy spin or those who look to add more spin to their games (and want to play with heavy spin).
Playing flat with this racket is meaningless (and maybe risky as well, though I wouldn't know). So for serves, you'd really have to put some more spin on them to control them. You can still hit everything very quickly through the court, but you need to use more spin to control it and gain back the accuracy you lose. In the end though, you can hit just as hard, if not harder than before, but with much more spin and safety. You just won't get nearly as much pace as a depolarized racket. I mean, you can still hit flat groundstrokes and flat serves with plenty of pace, but it's not where the racket really shines for me. If you're going to specialize in that, might as well depolarize your racket.
When using a depolarized setup on serves, I could still generate plenty of spin (same if not more than usual) to drop second serves consistently into the court deep with the same amount (sometimes more) of action and kick. The only difference was that those second serves were moving through the court at least 10 mph faster. My friend tried serving to me with one of my depolarized rackets and me using the polarized racket, and I couldn't even push the ball a foot in front of me. The ball was just so heavy, AND it came in faster than normal. A big server playing with a depolarized racket doesn't really have to worry much about holding serve. They just bomb a big first serve, then finish off whatever floater comes back. It's part of the reason Sampras had such an easy time on serve. Maybe 20% of the reason. His racket was heavier than most, and as such (with the spin and pace he generated) people had a difficulty keeping their racket stable and plowing through the ball at contact. Playing with a depolarized racket, most first serves were service winners and most second serves were essentially slightly slower first serves with more kick (compared to me using my regular racket).
Actually though, if you made contact around where 10&2 is, you'd get more plow through than with a 3&9 setup. Most people generally make contact at 3&9 though. Nate said pros generally hit higher up on the stringbed (hence the placement of Federer's string savers), but I doubt that. Pictures and slow motion videos at contact show that the pros still hit almost exactly in the center aside from a few shots where they'll hit it closer to the top (intentionally or accidentally I'm not sure).
And generally I read a lot, paid attention in physics when we learned about force, conservation of momentum, and so on (stuff that can be applied to rackets), and I actually experiment a lot with racket customization. I have 2 heavily depolarized rackets at 13.8 ounces that generate tremendous amounts of power, 1 polarized racket at 12.5 ounces (without overgrip) that generates tremendous amounts of spin, 1 lightly depolarized racket at 12.9 ounces that has a lot of power and slightly increased spin, and 3 slightly depolarized K90s (that I'm testing out to decide if I'll switch to this setup or not; 2.5 grams under the bumper) that are more comfortable during swinging and generate a little more racket head speed and spin/lift. My dad also uses a heavily depolarized racket (that he personally made through months of trial and error to slowly add and remove weight until he found the perfect setup) weighing in at around 13.3 ounces.
And one final word, if you polarize a racket, the more weight you add, the less you'll notice the inconsistencies of the racket, but you can easily fix that with practice time.
Oh, and the bit about adding weight 7 inches above the buttcap came from a John Cathen I believe. It wasn't my idea. I tried it out and it worked beautifully (solved the problems I had with depolarizing a K90 because originally I was reluctant to put weight under the grip fearing bulkiness under the leather, which wasn't even noticeable). Here's a step by step of how to depolarize your racket.
His ideas differ slightly from mine, but he's probably got more experience in the subject. Then again, that might be why he's seen as such a crazy person to some people.
That, or his nonstop ranting about concepts people don't understand because he doesn't explain them or their benefits too well. But he has a pretty solid grasp of what he's doing as well... Though he seems to change his racket setups far more than most people, and he goes nuts when a pro (like Federer) doesn't full on fit 100% into his beliefs of racket setups. When he found out Federer's racket wasn't as heavily polarized as he thought it was, he freaked out and went on a rampage.