Balrog Boss : I got some questions.

Hi, so I searched alot on the forums and couldn't find a thread with a guide or explanation regarding the ballrog boss.

1.is it just a boss or a PQ?
2.where do you do it?
3. any pre requisites?
4. whats the differance between 50-70 and 70-??? ( whats the 70+ range? 70-120 or 70-200? )
5.do drops bomb like zakum or somthing else?
6.Are there any guides? links?
7. - off topic but , whats the strongest NPC attack pot, stackable and non stacking.
8. is there a thread listing what people got from the new maple nx suprise thingys... the ones that cost 500 each from CS under the event tab.

Thanks ~