The sentences are the same in meaning. #2 is more formal and #1 is preferred in today speech. (You may use a object pronoun and a subject pronoun after 'than' with the same effect, but an object pronoun is better)
Yes, both are possible, but only #2 is avcceptable for formal/careful use.
I think it best, though, to avoid suggesting that informal usage is in any way 'better' than formal: they are simply suitable for different situations and purposes.