Add and Customize Pages permission not granted for SharePoint 2010 Contributors

SharePoint 2010 Contributor group doesn't have permission ''Add and Customize Pages". This permission is granted from designers and the above. This causes to error when try to adding webpart to the webpart page and customize webpart as a Contributor.

but the confusing part is OOTB webparts can be added and modified by the user who has contributor permission. When I search for that I found out that SafeAgainstScript=True in all the OOTB safe control entries. When we deploy WebPart using Visual Studio this SafeAgainstScript=False

Setting 'Safe Against Script' to false

This value is false by default which means SharePoint will not allow editing and configuration by site contributors.
If you want to continue to let a Web Part remain configurable, even bysite contributors, you can change the SafeAgainstScript attribute of the SafeControl declaration for that Web Part.

Solutions

1. Add "Add and Customize page" to the contributor group or Create custom contributor group with    this permission
2. Make SafeAgainstScript=True in Safe controls of the WebPart
3. http://technet.microsoft.com/en-us/library/hh272821.aspx