wallet desyncroniser or untraceable on the web of certain Cryptomonaies

[Mantis-H]

Hello

I would like to know why wallet of certain monaies are desyncroniser or untraceable on the web.
My seconds question what are the risks of mining monays or there is no wallet?
Can i lose everything? Or never be able to transfer the currency of the pool to a wallet ?

for exemple i whant wallet of powercoin and the web site is down http://www.powercoin.pw/
but i can mine this monaie on pool
can you explain to me how transfer if the wallet does not exist or desyncroniser


Thanks