Overcharging - will it be a problem ?

No.

what he said 😉

Also though, letting in run flat may be more of a problem. Its better to keep it charged at anytime rather than totally killing the battery.

that battery would have exploded however you charged it. Perils of non OEMs

The life of the battery charge repeated charge and discharge times, it should avoid the battery is more than power, this will shorten the life of the battery.Phone off for more than 7 days, the first mobile phone battery is fully discharged, adequate electricity and then use.

There are a lot of users are often in charge when the phone is open, in fact this will be very easy to damage the mobile life, because in the charging process, mobile phone circuit board will fever, at this time if there is foreign phone, may produce instant return current of mobile phone, internal damage parts.