Is Bitcoin network an Asynchronous network or a synchronous network?
In my understanding it is an asynchronous network: It works over the Internet. The Internet is the biggest asynchrounous network. An adversary cannot delay the transactions effectively if he doesn't control the majority of the hashing power. Therefore without making the asumption of a malicious adversary with that power, your transaction will eventualy be included in the network: the answer to your las question is no, the protocol is asynchronous and it will reach consensus.