With WM, do you deposit points in II, or do you book a week, and deposit a week with II?
pacman
WM owners don't book weeks for trading. For regular trades (not flexchange), if you get 2BR in peak season, your 10K credit will be automatically deducted from your account. 1BR is 9k and studio is 8k. If it's off season, 8k for 2BR, 7k for 1BR and 6k for studio (not sure for off season points

).
For flexchange, what unit size you get is not matter, all flexchanges (1BR or 4BR) are the same, 4k credits. WM deposit the weeks for you to II (after trading is confirmed), it is similar to what starwood does for SVN members.
One great thing of WM is, you can search with 3BR WM unit, it has great search power, and if you pick 2BR in Hawaii, only 10k (2BR credits) will be taken from your account (not 3BR credits your are searching with). So you can search with 3BR, and grab whatever you like (1BR, 2BR, etc...), then only the unit size you
get decides the credit number to be taken.
Once I booked Marriott Phuket Club (Thailand), 2BR, fourth of July week, and it cost only 8k WM credit, because 7/4 week is gold season in Marriott Phuket Club calendar. It wasn't flexchange. 8K WM credit is $400 MF, and plus exchange fee of $159 = approx. $560.
If you don't use your current year's WM points, they are automatically added to next year's points. Also, you can borrow next year's points to use this year for free. So all 3 year's points (last year, current year, next year) are equal to trade. For WM, points are just points, it's trading value is not changed by when you got the points.
I didn't try request first yet, all my exchanges were from instant online search, but I've heard from other WM owners that they got great exchanges by using request first (for tough season/resorts).