The eBucks wouldn't be a problem because they would belong to each individual account. The only problem that I see with sharing a PayPal account would come from trying to keep track of which eBay GCs were used for which eBay account.
I thought I'd read that you can only get 500 eBay bucks per quarter regardless of the # of eBay accts you have. I assumed they knew this based on the PayPal it's linked to. Maybe it's strictly by the name on the eBay acct?