Earlier quoted context omitted.
Hours to settle into $? Or hours to confirm the Bitcoin transaction at all?
To confirm the Bitcoin transaction at all. That's just how Bitcoin works - you have to wait for X new blocks to get confirmations from other peers. How long you wait determines your risk level.
Also, for something revocable like a domain name, there's nothing preventing Namecheap from giving you the domain name immediately, and then revoking your access to it later if the transaction ultimately fails.