<p>Don't bother with stats. If you have a solid shot at a 4 or 5 on AP Physics B or a 3, 4, or 5 on either of the AP Physics C tests you might as well take the exam. I'd suggest that you go ahead and take the AP Spanish exam because 1) you can't be entirely certain that the SAT score will continue to get you out of the language requirement in the future (don't have any reason to believe it would change, but it's not impossible) and 2) if you plan to continue studying spanish at Stanford you'll probably be slightly better of having taken the exam. I wouldn't bother with any exams that you can't get credit for.</p>
<p>Also, be sure to do either the SAT II or AP exam in any language that you think you might be able to test out of. Some of my friends didn't do so and now regret it. The SAT II is much easier than the placement test here (or so I hear).</p>