The easiest way to use Raspberry Pis in primary schools?

I really like the idea of Raspberry Pis for education, but I've not yet managed to get them to work in the primary school where I run my Code Club. The school has roaming laptops, iPads and iPod touches and no easy way to plug in Pis to screens and keyboards — there's just no room available for them.

Browsing through Simon Walters' (@cymplecy) latest exploits with ScratchGPIO and Scratch Interface Device (SID) got me thinking a little… I wonder if the following is possible:

1. Set up Pi with DHCP server to assign 10.x addresses (school laptops are on 192.168.x) and to have its own address set to 10.0.0.1
2. Set up Pi to run a script on startup that waits for Scratch remote sensor connections on 10.0.0.2 — then run ScratchGPIO with 10.0.0.2 as its host
3. Connect Pi to laptop with ethernet cable and USB (for power) — no other cables required!
4. Laptop should have wired IP of 10.0.0.2
5. Open Scratch on laptop and enable remote sensor connections
6. ScratchGPIO should start on Pi and be available to the laptop
7. Plug some hardware into the Pi and start controlling it!

Can anyone help test this out?