One more thing: I'd also like to see merc vendors on Normal and Nightmare difficulties report the stats of their high-level mercs correctly. In LoD, Kashya under-reports the stats of rogues over level 36 on Normal and 67 on Nightmare, Greiz under-reports the stats of mercs over level 43 on Normal and 75 on Nightmare, etc... if you hire a level 98 rogue in Normal difficulty, she'll be advertised as having 900 HP, but press "o" and you'll see that she actually has 1830! This needs to be fixed!
Q u o t e:
-Make something to allow completing sets easier (for example, improving the chances to get one of the items from a set if you already have one from the same set, or make the spawning system more like that the one for unique items, this is to say, only one of them can spawn at a single game, which would allow to find set items from a base item shared by several set items).
The best way to do this would be to dramatically increase the frequency of set drops in general. I've never seen 2 Cathan's Rings (or any other set item) drop in a single game, so your second solution is kinda dumb.