As a few other people have mentioned the 15% law isn't in force and is unlikely to be in the immediate future. Which is good news for all us tokers!
I always find it hard to recommend Coffeeshops because I honestly think that vibe is a very personal thing. You're going to have to walk away from the Centrum to find the most relaxed and non-mainstream Coffeeshops. Saying that, I always enjoy Rusland Coffeeshop (on Rusland just off the Kloveniersburgwal Canal which is around a 5 - 10 minute walk away from the Red Light District). There's always a chill vibe, a friendly budtender and some quality cannabis on offer. There menu is what i'd describe as old school with strains like Crystal and Power Plant so if you're looking for the newest mind blowing haze then it's not necessarily the place for you.
If you are looking for some of the newest strains or North American style strains, like Buddha Tahoe OG or Kandy Kush, then i'd recommed either Green Place Coffeeshop (on the Nieuwmarkt) or Voyagers Coffeeshop (on Geldersekade). Both of these aren't too far from the Centrum and always impress. If you don't mind a walk outside the Centrum then i'd recommend Paradox Coffeeshop (on Bloemdwarsstraat in the Jordaan), Yo-Yo Coffeeshop (on Jan van der Heijdenstraat near De Pijp) or Katsu Coffeeshop (on van der Helststraat near De Pijp and very close to Yo-Yo Coffeeshop).
If I were you i'd take a look at http://www.coffeeshop.freeuk.com/index.htm
which is a gold mine of information.
As for the window girls the price is still 50 euros for 15 - 20 minutes and for that you should get a standard suck and fuck with her being fully naked with mutiple positions (usually 2 or 3). Please check out The Girls section of this forum http://www.ignatzmice.com/forums/viewforum.php?f=16
for more information. Also it might be worth reading some of the Trip Reports posted here viewforum.php?f=14
to get a flavour of who is hot in town currently.
I wouldn't say I have noticed any particular closures of any windows recently although it is always a hot debate with people swearing the Red Light District has far less windows than their last trip and others (like me) swearing there has been little to no change. Check out http://www.amsterdam-red-light-district-maps.com/
for more information. He has documented the changes and the window count seems to be the same.
Enjoy your trip! I can't wait for mine! I fly out on 14th March 2012. Bring it on!