tested and agree with you the +1 skill is randomized.
yes melachite gems in ED takes for ever to get at least 1.
I had luck that in one ore vein I got three but that was exremely rare!
yes two enchantments of the same type do stack but only the % and the damage will be a between!!!\
like your example 8% chance for 12 poison damage and 10% chance for 36 damage will be, 18% change between 12 and 36 poison damage.
