I think you misunderstand me so let continue your thoughts to see if you agree?
pretend you download a live cd....highly recommended even if I do not use your hardware.....agreed.
But to run the live cd...on each computer....connecting your hardware via usb connector....is still going to need this cd to recognise your hardware/software......so each time you boot the cd....you have to connect a separate usb stick and mount it....and load the software from the link....and only then insert your hardware.
OR
you download an usb image and write to usb storage or download a live cd that can write itself to usb storage AND
then you install the Arduino software....as persistence....I explain that below
so you are not re-inventing the wheel....and taking up time....and not creating a bad impression for a ms audience.
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usb storage fall to 3 main camps
1) a true hard drive like install....writeable....and you can have your own home/name
2) livecd like structure...but detects usb stick with its /home folder....writeable....known as persist
3) livecd like structure but no persist...safe but not recommended for your case.
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I agree that minimum and fast to boot live cd/usb is the way to go
I do not have your hardware so can not recommend what to choose.
But heck....I use sidux 2009-03.....its not for beginners but xfce is very fast and sidux has scripts to allow cd to write to usb with or without persist.
a number of live cds offer similar tools to install to usb but differ on scripts etc
http://manual.sidux.com/en/hd-instal...-en.htm#usb-hd is worth a read.
2) As for the software that displays the buttons, what do you recomend?
I thought the software in top link was the answer? I am not going to d/load it as I can not test it without hw.
But a display manager is good....and sidux and most other good live cd/usb systems can autologin so I see no problem there.
ROADMAP
so it may take more than one distro download for you to discover which is the easiest and quickest to boot to a display manager.
sidux
puppy
slax.....are all fine choices but puppy is root login so watch that ok.
b) then install the software as from first links
c) Now the proof....when you install usb hw....does distro detect it fast....and then allow your interaction
I repeat I have no idea. I am only trying to point in you a direction of discovery.....there may be zero pain or there may be heaps?