For the nano, I used an external 3.3v regulator (with a common ground with the nano).
ch_pd was pulled to 3.3v always.
Note that I upgraded the firmware to 0922 version from here the http://www.electrodragon.com/w/Wi07c
so the hardware serial runs at 9600 by default.
I see a blue flash or two when it boots first .....
Also worth just using a serial converter, 3.3v and serial terminal (coolterm or something) - just to check that the basic AT commands are what you expect.