Once exchange is on the server, you cannot rename the server.
I am not sure about the “won’t boot” part, but for sure the exchange services won’t start if you do this.
build the server first, get it all ready, then install exchange.
No need for disaster recovery switches…just make sure the AD is the same, and then copy the DB’s in and load them up. As long as the AD is the same, exchange will match the accounts to the mailboxes and proceed upon its’ way as you want it to.