Is Bitcoin network an Asynchronous network or a synchronous network? Conventional BFT protocols work on weak timing assumptions, and if a faulty primary does not respond or forward a client's request a view change message is initiated by the backup nodes. Therefore, if an adversary delays the messages beyond timeout period, he can affect the network through a DoS attack.  The blocks in Bitcoin Blockchain are also time-stamped, therefore, I just want to confirm that does delay in reaching of any transaction or Block to maximum nodes affect the validity of that transaction/block after any timeout period?
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.