Not really - the third definition of religion in the OED is a completely different concept to the first two.  Someone may well say something like, "consumerism is the new religion" but that doesn't mean that consumerism is really a religion.  It is using the word more as a metaphor rather than literally.

If you want to be pedantic then you can argue that Buddhism is a religion but it doesn't fit the formally accepted definition of religion as defined by (1) or (2).

You are right though that Buddhism is an ideology that is willing to accept challenge and doesn't hold beliefs based on unchallengeable faith.  It has much to be admired for in my eyes.