There's absolutely no evidence of where Bush actually was between May 1972 and May 1973 (unless you care to enlighten me). The man just doesn't know enough to qualify him as being President of the USA - for one thing, good communication is essential, and the amount of times he's just talked a load of complete nonsense is just wrong. He's controlled by the big corporations and just plain doesn't care about your average Joe. The fact that he can (or could) fly a plane bears little on his current occupation.
As for the others, I don't know enough about them to comment. Reagan was controlled by his wife (that much was obvious), but selling arms to Iran/Iraq was a big mistake, you can't possibly protest that.