Hi,
I agree that Tasker can do the job, i have Tasker as well, but to be honest, it is equally as confusing as rooting the phone! And on top of that, between 99% and 100% of charge, your phone is put on silent, no brilliant in the case of an emergency.
You may as well just put the phone on silent, also i am unsure as to whether that would also mean that even in mid day when charging that your phone would go on silent between 99% and 100%, it just is not practical to me. Other people dont really mind.
Kind Regards,
Boseley