My one piece of Adwords advice is to try and get position #3. I've experimented with positions 1,2 and 3 and found no significant change in CTR, whereas position 4 drops off quite a bit.
Could be something to do with the fact that you can generally see the top 3 Adwords without scrolling down.
Good luck!
We see this a lot in our own adwords which advertise services from particular countries which are used by people from all over the world. Basically we pay for selling a widget from Thailand for example, based on what it would costs to sell a "widget" by the highest bidder just for that widget word.
To me it would make sense for relevancy and targeting to users needs (though maybe not for revenue) for the queries from the actual phrases associated with the "phrase" adwords to be listed above those associated with single words regardless of CPC.