Security & Privacy on iPod Touch and iPad w/same Apple ID

I had my iPod Touch and created an apple id account. When i bought iPad4 i sold the iPod Touch but i used same apple id that was registeredd in my iPod. Will there be no conflict at all with regards to application, photos and updates since I am now using an Ipad? I know that using a similar apple id will also update both gadgets at the same time. Now that the iPod Touch was reset and used by another user name/owner. Does the new owner of Ipod can still access my info? please help, i am worrying of the security and privacy. How can I totally deactivate my iPod account. Thank you.