question guys, the 200 ringgit SKMM thing. can be used in all digi outlets? or certain outlets only?

just got my nexus 4 in sunway pyramid digi centre. SKMM applicable.

a question here. many people told me not to overcharge at night. once it reaches 100% or when it stops charging, pull the cable out. i agree with that. but what about charging it constantly? I just got a nexus 4 and im afraid that i charge it constantly, like i charge it at 40% and plug it out at 70%, will it affect the battery life span?? need some clarification.