Well, there's no (easy) way to "unsimplify" ("complexify"??), so how about leaving it as it is for now. After you've (we've ;) ) tested the map, if you don't like it, *then* spend the time on simplifying it (and test again; can be done really quick, since it's just testing performance, not something complicated like playability).
From the sneak peeks you've shown us so far, it looks like you're putting in a lot of detail; I think it would be a pity to throw out all that effort because *maybe* WL can't cope with it. (If you would've asked me beforehand "Hej, Amsterdam looks really complicated, should I draw all the canals" I would've told you you're crazy and of course not, but seeing how you already did it...)
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I'm unsure how big your harbour and airport signs are exactly but wouldn't they fit in either the Western (upper) part of Amsterdam, and/or the North-eastern (lower right) part? Btw, technically Schiphol is located on land belonging to Haarlemmermeer, according to
http://nl.wikipedia.org/wiki/Schiphol:
|> **Het vliegveld ligt in de gemeente Haarlemmermeer** en bevindt zich ongeveer 15 kilometer ten zuidwesten van Amsterdam.
so shouldn't you put the sign (and the corresponding "airport-links") over there?
From a gameplay point of view, having an airport and a seaport in the same territory would create a massive hub of connections. Having two smaller hubs (in directly neighbouring territories) might be better, don't you think (or is that something which needs play-testing)?
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@Matma: Take a look at Netherlands Big; this territory is (well, by Dutch standards ;) ) positively huge.