That sounds very cool! Dust comes off again easily with some compressed air. Are the ducts level, and are there corners? I have driven a smartphone running IP Webcam
around on a robot before.
The ducts are level, thank Flying Spaghetti Monster. There are corners and T pieces, but the design I was considering was sort of a snake like bot with a short front section with 2 powered wheels (tank style steering), a thin midsection without wheels and a short rear section with 2 unpowered wheels, all with hinges between the sections. That way it should be able to navigate a Ø100 mm 90° T piece without problems.
As for the webcam: I was planning on using my phone as a remote controller (bluetooth) and putting a simple cheap webcam on the bot. That would only cost me about E25 + a 25m USB cable. Maybe that USB cable can also let me put a cheap bluetooth adapter on it for controlling the Mindstorms because steel ducts aren't all that good at letting a signal enter them. That would probably mean that I would need to use the PC to control it as I don't expect my phone will allow for an external bluetooth adapter.
As for the dust: I would mainly worry about dust entering the motors, as they are not meant to be opened and cleaned. The parts can be cleaned in multiple ways, washing them is always a good and simple one, assuming I can disassemble them.
As added bonus I would be able to use the build in my engineering portfolio, as I plan to switch jobs quite soon. Mostly that will be 3d CAD stuff but this can be a cool addition, to show practical skills and prototype building.