Intuitively I would assume that a single event would either not release enough energy to start a feedback loop or destroy the planet altogether, but I have no idea how to calculate that.
In some regions of Germany, beer wasn't traditionally as common as you might expect. By watering down wine, you get a beverage with a similar alcohol content like beer which you can drink in similar contexts - for example, it's not a great idea to drink undiluted wine when you're sitting outside on a hot summer day
I don't think making semiconductors at home is explicitly illegal anywhere, but I doubt hobbyists can legally buy or synthesize many of the chemicals you'd need
If you complained to most Germans about an S-Bahn system with an average delay of 4 min, they'd think you're Swiss - according to the German railway statistics, any delay less than 5 minutes and 59 seconds counts as 'on time'
I don't think you can damage anything by doing that - maybe you'd run into problems if the keyboard needs more current than the USB port can provide, but even then the keyboard just wouldn't do anything
As far as I know, the Windows UI technically doesn't need GPU acceleration, but it does depend on DirectX - the Windows 8 developer preview included a software renderer so that Aero Glass worked even without GPU drivers.