Your DNS should be changed with your DNS provider. This might be the same as your registrar, or it could be in your cpanel. We can't answer that one for you, but my money is on CPanel. If your registrar has "nameserver" records, do not touch these.
Did you put a full stop
. at the end of
ghs.google.com? You've done it correctly in step #3. DNS propogation can take time though, so if it's taking a while, it depends on what the TTL (Time To Live) of the previous record was. Hours is often not enough time to wait. Sometimes it takes days.
See above. DNS propogation takes time, especially if the upstream DNS servers are badly behaved (smack, bad DNS). What you've got there looks totally correct though.
You'll need to contact DomainCentral's support and ask them for additional TXT records. Although to be honest from what I've read in the past, you're lucky to even have one.
If you're really serious about it, you might want to consider seperating your DNS from your hosting provider. This gives you the ability to dump your host without having to re-configure all your DNS, and also means that you can guarantee that your DNS settings are correct, without having to guess where you're meant to go to get it work.
-- Update --
I've done an
nslookup on your domain, and the MX records look totally correct:
> set q=mx
christian-linux.com MX preference = 10, mail exchanger = aspmx3.googlemail.com
christian-linux.com MX preference = 1, mail exchanger = aspmx.l.google.com
christian-linux.com MX preference = 5, mail exchanger = alt1.aspmx.l.google.com
christian-linux.com MX preference = 5, mail exchanger = alt2.aspmx.l.google.com
christian-linux.com MX preference = 10, mail exchanger = aspmx2.googlemail.com
aspmx3.googlemail.com internet address = 22.214.171.124
aspmx2.googlemail.com internet address = 126.96.36.199
That all looks correct, so I'd say it's just a propogation thing.