Defintely call and call again if they cannot/will not help you.

I had a re-route when they cancelled their BKK route.

KE was GREAT - coach was easily comparable to C+ on DL space wise - I actually think better and the service was outstanding.

When I returned everything posted to my account was wrong. I had to call in twice.

They finally updated my MQM's, (total of 19K+) MQD's and the MQS to the correct amounts. Hang on to your original confirmation and ticket number.

As far as booking seats - I was able to do that a few months in advance, by calling KE - only down side was/is exit row they only do day of and AT the airport.