I have Bitcoin (GUI version) running (and mining) on two machines, but can obviously only forward port 8333 to one of those.

What implications does this have for the machine without incoming connections?

Will it be able to "find" coins while mining?

Will it be able to receive coins by transactions (more precisely: will received coins be displayed without my intervention)?

Both clients are at the top of the block chain and have connections displayed in the status bar.

Will the answers be any different for "bitcoind"?

Best regards,

Andreas