So, +5→+12 (without adv) 8% Chance ?
With Vip (30%) , Luck Stone (??%), Luck Dress (4%?) , Luck Buff (15%)
30+4+15+??~49%+8%~57%
So, if i use everything the chance is about 57% ?
VIP(30%)-, Lucky Stone(1%)-,Lucky Dress (4%), Lucky Buff (15%)-,Powder 14D(%8)-, Elixir Weapon (12%)
30+1+4+15+8+12=70% ?
So, i think all ppl destroy or fail with all items to % 70.00 chance !

If the alchemy was fully 100%, I must say, it will be really goddamn boring. Alchemy is fine as it is now. Alchemy is a part where you have luck or not .
So what if a item gets down in plus if it fails, so what if it gets destroyed. You can always try again. We players do ask to to much when it comes to a private server.
Think about that mates

Joy, elixier and luck are already in that %.
Look at Navmesh's post ^^
Hmm , than you must ask Navmesh

All info is on chart, no more explanation will be given.