Dear customer,
1.The Grove jack you can plug, but some kind of sensor is use in analog or only I2C so may be it should depend.
- You can use I2C connect many sensor one by one but not connect with base shield, it is for Aduino or Seeeduino board to plug with.
3.It also depend, there are TX, RX, VCC, GND in Grove jack that mean you can receive or send signal with it.
- You mean without Bee can it charge?Yes of course.
More detail you can view in our WIKI.