I last week finished reading and marking the CWSPv2 study guide as well. Thanks for your comments for corrections. I have as yet had no discussion with the three authors or their publisher regarding their plans for an errata list. This book was produced with the blessing of The CWNP Program but otherwise independently, and I am no more than a friend to all.
I agree with you that CAPWAP is not squarely about WLAN security, but I benefited significantly from chapter 18 and the self study into CAPWAP it provoked. And don't the most recent CWSP exam objectives include WLAN controller and light weight AP issues? Cool.
I hope this helps. Thanks. /criss