My disorganized thoughts...
Regarding the training of Anakin: At the end of TPM, Yoda essentially tells Obi-Wan that while he personally objects to training Anakin, the Council feels otherwise. My sense after watching TPM several times and AotC twice is that the Council has become mired in politics and the Jedi Order has become stiff and inflexible. Let’s face it, its been around for at least (according to the movies) 1,000 years (longer if you take the EU stuff into account) and probably has evolved into a fairly rigid institution draped in lots of history and tradition.
Regarding balance in the force: I have to agree with Lady Dragon that balance in the force makes more sense if it is not thought of as equal amounts light and dark. I believe GL is often quoted (although I have never seen the actual transcript of this quote, so take it with a grain of salt) that returning balance to the force meant removing the Dark Side from the galaxy. I think that this explanation makes more sense than having equal light and dark, which any reasonable Jedi would quickly deduce means a major culling of the Jedi herd.
Regarding the loss of control by the Jedi: I have to admit that this plot revelation surprised me a bit. But it nicely explains why the Jedi are not as effective as in the past. But what is the cause of this? I believe this has to do with the manipulations of the Sith over the past decade or two. Sidious has been manipulating events that have been causing conflict in the galaxy. This conflict causes a disturbance in the force (because of the powerful negative emotions of fear, hate and anger that are generated), which limits the Jedi’s ability to see the future or even the present. I believe that when the Clone War starts Yoda comments that “the shroud of the dark side as fallen”. Or something to that effect.
Myrdden