I fish out of my boat but.......
I just recently bought a kayak that would be perfect to outfit for fishing, which is something I have plans to do. I do not see reason why one couldn't crappie fish out of a Yak. The only limitations of a Yak vs a boat would be ease of running from spot to spot quickly.
I've seen guys on Alamo crappie fishing out of a kayak along with Yellow Cliffs/Cat Bay area of Bartlett. So go for it AZFishing03!! I'd love to hear how you've set up your Yak and fishing reports.
One of these days I'm going to leave my boat at home & fish out of my kayak and beat the pants off these guys at one of our club derbies.
One thing - the most important thing regardless if you are in that big bass boat or in a kayak is Time On The Water!! There is no better way to learn.