Never build a console where the user have to keep more than one accessory charged to play as default.
This, I think, will be the consoles downfall. Parents of small children will just get tired of having to keep stuff charged so their kids could play.
At least on Wii we had batteries, so kids could just change them when power run out, but here, especially with multiple controllers, trying to figure and remember what part is charged and what is not, well, I'm not going there.
this controller is the only thing you have to charge.
the console itself charges itself while in the dock.
the pro controller is optional and not needed.
If that's the standard grip that comes with the console then no, you can't use it to charge the Joycon's. In order to do that you have to buy the $30 accessory called the Charging Grip. Without it the only way to charge the Joycon's is when they're attached to the console itself.
My problem with the Switch is that it launches with nothing. Zelda is the only game on the Switch that I'm interested in and I'll get it on the Wii U. There's literally nothing to do on the console itself other than play the few launch games. For me to buy the thing it needs Virtual Console, Netlix, internetbrowser and a few more games.