From what I read, it seems like he/she is saying two things: 1) Make it possible to scroll all the slots with one try. 2) If [1] is in effect, make it so that it will only have one try at all success or all fails.
To me, [1] seems reasonable, [2] does not. The post is pretty much asking to make a 15% success rate scroll for a 7-slot weapon to have 15% success for perfectly scrolling the weapon instead of the current 0.15^7 = 0.0001709% to perfectly scrolling a 7-slot weapon with 15% scrolls.
It is those little chest in the Central Hall. Drop one or more key on the chest and wait like 5 seconds then it will open by itself. NOTE: All key dropped will disappear, but only one candle will pop out.
