Just re-reading this thread, not sure if I got it right or not. Adventurers are limited to 100% by gear and can go no further by normal means. Does this mean unique items will not be beneficial for an adventurer at 100% skill level already? or can the bonus still apply to adventurers at this level?
No matter what, adventurers cannot increase their skill past the level their gear allows. Thus, bonuses from unique items cannot improve adventurers' skill past 100%.