The pool was "broken" on monday and tuesday. So many people don't get their coins or stopped mining through the pool. But from yesterday evening the pool seems to be OK again. So I think you should get more coins in the next hours.
Started to mine in the morning, can see some coins in Balance, but it hasn't changed for more than hour, maybe there's a problem again...
I don't think so. hashrats looks normal and block height is same on pool and explorer. The balance will grow after 360 block confirmations. So you have to wait between 12-16 hours after you start mining until balance will grow an coins come to wallet. The balance you know see is "old" from last time you were mining and don't reach 20 coins.