1) that was actually a feature, but I'm not sure if it is a good one. Not really decided yet.
2) Ugh, that's another thing I wasn't aware of. Are you sure only one works?
Yup, luck cannot buff chances higher than 80%. Adding more item chance / quality always gives you an improvement, but with diminishing returns. So the higher it is already the less adding more will benefit you. So there is no hard cap as it is with luck.
Thanks for answers ;)
1) Honestly it concerns only power balance Iron Man via "eating" dark items. So yes, it's on your professional decision. Forge leveling isn't a problem with or without stacking (except with - it much faster)
2) Yes, Painting of Solea definitely don't stacks. It's easy to check, with 20% chance 5 copies don't give 100% miss.
3) Oh one more. When the tower misses, the “miss” pop-up message does not appear.