Requirements to register and sell on eBay.com (NON-US resident)

[scotch]

I have a Canadian selling account on eBay.ca. I am looking to target US market. Therefore I would like to create a eBay.com account, but have A few questions in advance.

1. Is it legal to have two selling accounts on Canadian and US marketplace ?
2. Do I need a US based address to register eBay.com
3. Do I have to collect Tax from US customers ? (I rather not to, because I am NON-US resident, so filing will be a problem)
4. Do I need a US business number to register on eBay.com ?

Please provide advice, if I am missing something let me know.

-scotch