I don't understand one thing : If I get paid an amount of 0.000055 BTC ore more, how come the fee is 0.0005 ? The fee is ten times bigger than the amount I was paid?
The tansaction fee is based mostly on the transaction size (in kilobytes), not its amount (in BTC).
Even more: the bitcoin protocol is quite unfriendly to small transactions to prevent spamming the network. If the transaction output is larger then 0.1 BTC, then the fee could be leveraged (more on fee generation algorithm here)