If you don't use namecheap's dns servers, dns requests for your domain do not go to namecheap for redirection. They don't go to namecheap at all. Your specified dns servers get registered with the top level domain servers.
No. The zone file lives on the nameserver (DNS server) which Route 53 provides. Namescheap registers a list of nameservers for your domain with the TLD.
An over simplified example for looking up "news.ycombinator.com":
1. First query the TLD nameserver for all ".com" domains asking for the authoritative nameserver(s) for "ycombinator.com".
2. Next query that nameserver for "news.ycombinator.com".
zargon|12 years ago
sparagi|12 years ago
daigoba66|12 years ago
An over simplified example for looking up "news.ycombinator.com":
1. First query the TLD nameserver for all ".com" domains asking for the authoritative nameserver(s) for "ycombinator.com".
2. Next query that nameserver for "news.ycombinator.com".