BTER is back now. I see no message regarding it on the site. What happens , when people log in to the site. Can they withdraw their funds ?

As they said on their twitter feed, they're working on withdrawals, starting with CNY, USD and NXT

https://twitter.com/btercom/status/568944687257530368

Thanks, Yeah saw their tweet right after posting this. Best to get your coins out of there

Yep, whoever has funds there, take them out ASAP...

a bit off-topic question: did Mintpal repay all their customer's fund ?

No, not all. Only the funds that were avaliable to V1 were possible to refund.