Both are ok, but "mini" sounds more normal/casual/general :)

Your suggestion is both wrong and unclear. Schools don’t usually have museums, and museums don’t display safety data. What you are describing would need more explanation to be meaningful to an English speaker. Maybe it’s a ‘safety room’ or a ‘safety office’ or a ‘room containing system information’ but even those words would need more explanation.

I would say either or, but it would be good to make it suit the area. Micro could be a great match for a science based area, whereas mini is less scientific and informal, appealing to general readers.