EvilZone

I am looking into creating a device that I can plant at unsecured WiFi spots in my area, I've got all the hardware and casing done, I just need any and all ideas on how to run a VPN sort of thing through it, and also to be able to remote control it, whilst also the device not logging anything. Another issue is power management. I'm using the b+ which uses a maximum of 1 watt, my current power source for it lasts 42 hours under continuous use, so either I get a better power source or is there some way I can remotely turn it on and off when I'm using it? I'd also like to use it as a cloud sort of thing, I can use a 1TB USB on it, I would also be expecting to have multiple of them. Thanks in advance.