Is China Manipulating the Yuan? Should We Care?

According to Treasury Secretary Timothy Geithner (in his testimony before the Senate Finance Committee):

President Obama - backed by the conclusions of a broad range of economists - believes that China is manipulating its currency. President Obama has pledged as President to use aggressively all the diplomatic avenues open to him to seek change in China's currency practices. While in the U.S. Senate he cosponsored tough legislation to overhaul the U.S. process for determining currency manipulation and authorizing new enforcement measures so countries like China cannot continue to get a free pass for undermining fair trade principles. The question is how and when to broach the subject in order to do more good than harm.

Q1: Why does everybody complain that China "manipulates" its currency, but nobody complains that Hong Kong "manipulates" its currency, even though Hong Kong has used a currency board to fix the Hong Kong dollar at the same level for the last 25 years (see chart above back to 2000 - Hong Kong dollar has been at the same level since 1984)?

Q2: Is it fair to accuse China of "manipulating" its currency when the yuan has appreciated by -17% since 2005 (see chart above)?

Q3: If China is "manipulating" its currency, the manipulation is to keep the dollar artificially high. Why should we complain about a strong dollar, when that translates into lower dollar prices for American consumers and businesses buying Chinese products? What if China sent us its goods for free, as a form of foreign aid? That would be even better than an artificially strong dollar, but an artificially high dollar and "everyday low prices" for China's products aren't so bad.