LiPO reverse polarity protection with PFET & charger
No you can't just attach the charger to +Vbatprotected. The whole point of that PFET (with it's gate hooked to GND) is to effectively operate as a diode, but without the pesky downside of a 0.7V drop (i.e. because it has a low drain-source resistance when it's in saturation).

Even if that wasn't the case, I wouldn't count on a PFET to handle charging current which can be quite high. Just hook your charger to +VBAT directly.