Well Bitcoin is not really anonymous by itself, but yes. Namecoin is exactly the same as Bitcoin except for the added features.
and the protocol would need some major revisions and would need to be completely restarted IMO
1. cheaper names
2. do not destroy coins, ever
3. the cost of the domain is hard to fairly determine, but if the amount of domains registered per block, and amount of "active" coins were taken into account, you get set prices pretty good
4. need a utility that does not work via a modified dns server, surf with your own blockchain
1. Names become cheaper over time until the only fee left is the transaction fee.
2. Why is that important?
3. Actually the cost is pretty easy to determine. http://dot-bit.org/tools/domainCost.php
4. Yeah, not yet implemented into the client itself but in the meantime there's this: https://masterpool.eu/proxy