What if you ran scripts on your phone and computer so that it would appear as if you were browsing the internet and using your computer during your regular usage times?
Also using public transportation (and paying for it in cash) will help mitigate the first issue your brought up.
Personally I had the idea a while back for a sort of time-release dead drop. Stuff a Raspberry Pi into a fake power strip, put your seekrit information onto the SD card, and go plug it in somewhere in a city you 'happen' to be passing through, near to a public wifi spot.
Then a year later it wakes up and uploads the data publicly via Tor and self-wipes. Even if it's traced back to the Pi, they'll have to trace the Pi back to you (you bought it untraceably, right?).
Also using public transportation (and paying for it in cash) will help mitigate the first issue your brought up.