If you were going to start a competitor to Wikipedia, how would you set it up?

Personally, I'd probably permit anonymous users to create pages, adopt a 1 warning rule for vandalism (vandalism after warning would result in a block), replace NPOV and Verifiability with Truth (and therefore legalizing original research) and greatly reduce the criteria for notability. I'd also block all open proxies and school computers from editing anonymously (though they could create an account at home on their real connection with which to edit).

If you were starting a competitor to Wikipedia, what policy changes would you adopt?

get some books & start from there..
its not that easy to be a compititor to wikipedia..don't mention its in many languages..

First off, I would probably start a team and advertise the company before it was made. However, it's hard to compete with a large website like Wikipedia - it is, literally, the online encyclopedia.

Many of the policies on Wikipedia were created in response to one problem or another. It is difficult to balance everyone's needs perfectly.

You may want to read about Citizendium which was started as a Wikipedia competitor. They have strict identity requirements.

its sorta impossible competing with a giant like wiki
as for vandalism the American government is constantly changing correct info false info in order to hide the truth

so how would you stop the biggest vandals of all?

well first of all I wouldn't even try to do something like that but if I did would go to the professionals "Geek Squad" they are the best