What OS version came on this phone? KitKat was the original but has been updated to Lollipop. Settings-About Phone-Software to check. Did the phone recently download a large OTA update? If so, there may be app conflicts.
I've had this phone a week and had issues from the get go. I brought it to Verizon to do the initial set up and they did the updates and when I got it home it took 8 hours to charge and was too hot to even touch. I pulled the battery out for a minute or 2 and put it back in and it seemed to solve all the issues - no over heating, was rapid charging again and was able to download apps. That lasted about 2 days and it is right back to taking 8+ hours to charge and over heating
Sounds like they allowed any previous apps and data restoration to restore to the phone when setting it up from perhaps your last phones Google backup, if you had an Android previous to this phone. This is inconvenient, but something I suggest and something Verizon will insist upon at some point: Factory Reset the phone and DO NOT back up any data to the Google account and DO NOT restore any apps or data when re-setting up the phone. Factory reset then go back to the Play Store to My Apps and download your apps fresh. Restore any other media like music, videos, pictures and files from Drive, Cloud, wherever. I found that at least with the LG G2 and G3 that after coming from KitKat to Lollipop, that the apps from the old system are not always compatible with the new system.
Thanks I'll let you know if this solves my issues later - I'm pretty sure I have my pics/videos saved to google photos already so I don't have to back them up again and I'll re install the apps after as well.