Welcome to FlyerTalk, Simon.

1. NBO-AMS, operated by KL, is going to be hard to get seats issued to you. Call the KL ticket office in NBO (if they have one) or call KL in the Netherlands and they should be able to issue you a seat assignment. NWA.com won't let you do this.

2. You can definitely try to go standby for an earlier flight from DTW. I wouldn't pay the extra money unless it's very important that you get on an earlier flight. On the day of arrival in DTW, after you clear customs & immigration, go to the gate for the next TVC flight and ask if you can go standby. Your elite credentials may help you get on ahead of some other folks, but if the flight is sold out you will probably be out of luck. You will have to do this for each earlier flight than the one you are scheduled for.

3. Your bags might become an issue. The gate agents will probably tell you that they won't accept you on an earlier flight because they can't transfer your bags to the earlier flight. The rule here is that you're supposed to be on the same equipment that your bags are on - otherwise they have to take your bags off. Now this turns into a catch 22. Because you have such a huge layover in DTW, it's likely that the baggage handlers will just throw your bags onto the next TVC flight (or at least an earlier one) and they'll be waiting for you at your destination. Clearly that breaks the fly-with-your-bags rule. Apparently, if the airline doesn't tell you that they are moving your bags on an earlier flight, it's all OK; but if you ask to go on an earlier flight and the airlines knows your bags won't be with you, they sometimes won't accommodate you.

Good luck.

-RM