From my reading, you only assume the stats of a lycanthrope during the full moon and you need to make those WIS saves in order to not be an NPC until sunrise. Anything other than full moon involuntary changes and you only get the four things under statistics on page 30.
Until you pick up the New Moon feat your voluntary shapechanging is still mainly ruled by the curse, so it isn't nearly as potent as when the full moon rises.
So...
- You can voluntarily transform just from contracting lycanthropy whenever you want, subject to the rules under Hybrid Form.
- You can't voluntarily transform on the nights of the full moon at all. On those nights you are transforming whether you want to or not.
- You don't get the stats of a lycanthrope unless it is during the involuntary transformation under the full moon and you are stuck with those stats even if yours are better.
- If you want your voluntary transformation to be good, you have to learn to control the curse and that means taking a new moon feat.