Not to rain on your parade, but this is one of those instances when it probably makes sense to NOT buy a RTW ticket. Just because you want to go around the world does not mean it makes sense to buy a RTW ticket. My last RTW trip did not involve a single ticket but simply combined several one way tickets purchased along the way. The significant advantage to this was that it provided ultimate flexibility. Nearly as significant was the fact that the total itinerary: JFK-MAD-HEL-BKK-NRT-JFK cost $1750. This included business class in ANA on the BKK-NRT-JFK legs. If I had gone economy on those legs the fare would have been $300 less.

You'd be amazed what you can come up in terms of cheap one-way tickets in places like Madrid, Bangkok, etc. I look at your itinerary and it just seems to me that someone in your situation would benefit highly from the ultimate flexibility to do as you please along the way. I suspect you could very easily cobble together your itinerary as you move along cheaper than a RTW ticket.