Just for general info.
Heard from a reliable source that its always better to factory reset brand new phones, then match imei numbers and check device status and binary status from download menu. The status should be official.
I have seen many cases in which phones were showing original imei matching with box and phone label at back, but after factory reset or reflashing firmware, it shows some other number.
@kick_in
Check specs on antutu, cpu-z or phoneinfo+ (paid app that shows more useful info than antutu and cpu-z, including refurbished status etc).
As explained above, task manager only shows ram available to the 'user'. The ram shared by GPU or reserved by android system will not appear on task manager.
Those above apps will tell you total and available ram both and total should be 1.35GB (approx 1378 mbs).
Reflash firmware and then factory reset.
ADB commands gives direct access to recovery or download mode. That's what he said not to do.
Adb reboot download
Adb reboot recovery