This would describe a premise like “drinking is wrong”, but the argument uses a correlation as support instead. The problem is assuming that this correlation establishes a causal link.

This is irrelevant because the conclusion is simply that this effort seems to be successful. It doesn’t matter if another method could be more successful.

This describes the causation-correlation fallacy found in the argument. The premise only establishes a weak correlation between those who take the pledge and those who abstain from drinking, but assumes that this means the pledge is what’s causing people not to drink.

The argument doesn’t employ conditional reasoning to reach its conclusion. There is no condition that is sufficient to produce an outcome. The conclusion identifies a supposed causal relationship, but is flawed because it only cites a weak correlation as support.

These two claims are logically equivalent, so this doesn’t speak to the argument’s flaw. The argument’s problem is citing a weak correlation as evidence for a causal relationship.