Getting military grade sure... but you only need a half decent chemist and theres 100s of ways to make explosives from every day chemicals that in enough quantity would do the same thing - off the top of my head fertilizer/some stuff with nitrates is the only one thats really actively tracked.
Not really, if you want them to work well and actually have a shelf life long enough to make the quantity needed you need quite sophisticated set up.
Plus improvised explosives/fertiliser explosives take up a huge amount of space and someone would demand to know why you where shipping tones of material up their building.