improve Form dir structure

I think it's better to put all form models under /protected/forms folder instead of /protect/models, models should only keep data mapping classes. It's a clearer structure, at least for me:)

Form models do do data mapping, just as much as active records do.  And form models inherit from CModel, so I think calling it a "model" is just fine

You can certainly put them under 'forms' directory. Yii doesn't enforce you to put them under 'models'. In fact, if you are working with a system having hundreds of tables, you may also need to subdivide them into different directories.