Greetings,

Regarding "scripting" language take a look at the Arduino development language. This is a minimal subset of C which has a designer built in Java and complete tool chain.
http://arduino.cc/en/Reference/HomePage
http://www.nongnu.org/avr-libc/user-manual/index.html

Regarding use cases:
Kind of reminds me the Bitcoin payment protocol:
https://github.com/bitcoin/bips/blob/master/bip-0070.mediawiki
Although I'm not 100% sure at the moment how to tie this together.