About the trick weapons: the description between [ ] is the weapon's ability - in both forms. The base form allows the character to perform a quick and accurate blow, the alternate form a powerful blow (with increased effect), and you can take advantage of the specific ability of the weapon in both forms.
Roll lower attribute means you must use your lower attribute to gather dice for your pool.
I.e. if you have Prowess 2, Resolve 2, and Wit 1, you will roll 1 die.