I think this mining world is great, but could it change some prices here and there? For starters, gunpower/tnt will loose cost. More tnt might be used in the nether and maybe our first nether bans. Now i know this isnt a huge change and im still happy with it, but tnt will go down to maybe $5 and gunpowder will go to $0.50. Just a thought. (Not an arguement, just a statement) I know this isnt a huge deal, but there could ALWAYS be problems with the smallest thing.
Pretty sure its like the mobs in the nether, they are spawned when the map is spawned and....... once they are gone, they are gone. Hence why you won't see any after the first few days because people have ran into them and killed them.
Nope. I myself have built a "creeper spawner", a large dark room, and it works fine at spawning creepers. It just takes some time.
Good to know that will work there, I accidentally built one on my single player game when I generated the world, its called everywhere outside my front door not lit up like high noon.