There is really no methods to avoid account verification. When something suspicious is happening with your account Skrill is instantly going to freeze it until you complete the full verification process (including a selfie with your camera). So the answer to your question is yes, all accounts are locked when Skrill ask for verification.
Services like skills , paypal etc need account verification and they cannot let you withdraw without verification. The main reason for this is to prevent money laundering so that the person sending the money should not be anonymous.
