Barr already said he didn't support any of those things at the Federal level.
He doesn't oppose them, either, though. The LP candidate should be whoever can most effectively draw new people into the liberty movement - think of all the people there are now who were introduced to liberty from Harry Browne's campaigns.
Then in 2004, Badnarik won the nomination, although he was considered the underdog before the convention, based mainly on his performance at the debate. People saw that he was effective in communicating liberty, and voted to nominate him.
Ron Paul, although I disagree with him on a lot of things, was pretty goddamn effective at getting people to follow him. A fair number of them will be burned-out after the 2008 campaign, but at least of a few of them will become libertarians in the long-term.
We won't get that with Barr. People will see another fucking politician spewing useless fucking rhetoric, and not telling them anything they haven't heard before. The LP candidate will no longer be a stand-out who attracts people who finally realize "wait a minute, this is fucking retarded". He'll be just another talking head in a sea of talking heads.