A:AnswerThis dual charger has not been test fitted with the Xbox Elite controllers. The best option would be to test fit the controller in the charging base. Best Buy does offer a 15 day return policy that would allow you to return the unit if you do not like the fit or if it does not charge the elite controller.
A:AnswerI actually believe you can.
The way the charger works is by a pressure sensor. If you can find a way to make the charger packs stay on the pressure trigger, I'm pretty sure that the packs will still charge.
A:AnswerThe batteries on mine last a couple days between charges. I guess it all depends on how much you game, I'm only at about an hour or more a night.