Any of this is plausible and may be required in any legislation. But when it comes to Bitcoin, it's quite easy to find a legal solution to get rid of if or pervert it:
Just add a requirement that VAT & friends can be processed in real time:
http://bitcoinmedia.com/the-brave-new-world-of-mobile-payment/This would IMHO take care of Bitcoin, without even targeting it. It would force the payment providers to implement an RTPay gateway.
Yes and no. As always, what we end up with will be more complex than it appears. There is an incentive structure that makes Bitcoin appealing no matter what stigma is projected on it.
Very similar to tax havens and countries friendly to international business corporations or trusts, there will be regions that openly offer the flexibility and freedom to use Bitcoin without backlash. Much discussion has been made about how Bitcoin reduces 'friction' in finance. When benefits and 'a better way of doing things' become apparent, they will eventually be adopted even in spite of opposing pressure.
There might always be VAT and government interference, but legislation can only delay or mask beneficial ideas and practices. No gathering of politicos can wave their collective magic fountain pen wands and make Bitcoin disappear any more than they've been successful at making Bittorrent vanish, because time is not on their side.