iTunes Parental Controls and in-app purchases

I know that iTunes is planning improvements to Parental Controls for in-app purchases.

As a developer, how do I best use this?

1. Will parents be able to set a control on all ecommerce apps/apps that have in-app purchases? Meaning will a parent just make a single setting change on their phone and it will apply to all of the apps where you can buy something?

2. When the parents authenticate, will they authenticate at log-in with a 15 minute timeout the same way it works now?

3. As a developer do I get to use this for free?