But now you have an additional point of failure. You would need a very reliable DNS provider to host that CNAME. It increases your flexibility when CF has an issue, bit it does not necessarily increase the reliability of your site.
Yes, but if all your fancy names are simply cnames, you can use normal zone transfers to copy between servers, and use servers from multiple providers. Most recursive resolvers will retry requests against multiple delegated name servers until they get one that responds (or they all fail to respond). It adds some delay, so you wouldn't want the servers to be down often, but it's tolerable.
