Crowduino & XBee - Voltage Level?

Hi all,

I've got a Crowduino board which I'm planning to use with an XBee module, and I'm a bit unsure of a couple of things.

The link here (Crowduino v1.1 - Elecrow) seems to indicate that if I want to use an XBee in the Crowduino, I need to switch the board to using 3.3v logic. However, from what I can find, this will switch all the pins to using 3.3 volts instead of 5 volts. Given that I'm going to be using a couple of other chips with it (a MAX7221 LED driver and 74HC4067 multiplexer), I wanted to check if these ICs would work with a pin voltage of 3.3v?

The instructions also say to solder JP1 (jumper 1) at the rear of the Crowduino, but they don't indicate if this is required to use the XBee, or just if you want to be able to program it remotely. Can anyone provide clarification on this?

Cheers,
Tbdanny