Say Gold maybe you could steal some ideas from the Bounty Hunter of SWTOR and use the entropy itself as an energy source. There's simpler stuff like Flush Coolant which would visually resemble the venting nature of the devices, to Reload Coolant Cartridge which ejects a heated cartridge for a chilled one probably can be refilled with any liquid that has a energy of heating.
This also allows Dawn Star to Reverse Quantum Frequencies and fire off a Starlight Breaker using all the residual entropy in the area.
After all, playing around with entropy is what real magical girls do.
Also, in my head fanon, there's an player-driven economy in Accel World centered around Burst Points. Most people would prefer to PVP or just troll one another (Goonswarm does resemble the Society somewhat), while those with loftier goals fight in their own ways (the old Kings regime), and the rest are just Merchant Guys, Crafters, Miners, Ratters, Traders, Thugs, Pirates...
Your game, your way. (TM)
