i finally finish the game in hard with all golg medals,all guild missions and the 100 stones in.....85h
i do not anderstand a world of jp,,to item quest if there is not spot in map :
-you have maybe already the item the storage or you need items from yellow spot,there is 2 missions from SDF08 ask item you can eventually gain when you destroy cocoon second one ask 30(not the one you gain a lot..)
the only missions that take me time was few destroy missions, some targets apear in random in smal number,
if you found one you can eventually enter a base and back to make reapear,but with random spot it can even not work,
if you really do not found try eventually cave or stages,(and back regulary in can give 1chest with good items to build units)
i remenber a quest in desert :take me 20mn to kill 9/10...i take me 1h to found a last!