A hard reset should solve both of these issues. Google Play will save all of your apps and the One has a unique way of finding the apps that were installed prior to the reset and reloading them. As for your pics and vids and other items, as long as you don't choose to wipe all memory none of them should be affected by the reset. If you are overly concerned or worried Google + will save all of your pics and vids, your other items can be saved with any backup app. My Backup Pro is a paid app that offers a free 30 or 14 day trial to back up your SMS and MMS items, and your call history. Between Google Services and Big Red's Backup Assistant you should have all of your contacts back once you setup your device.