I played it. I think you should get a point in flail and get flail of ages so you have an item to kill clay golems with, and that slows monsters. Or else you can get the staff of magi and put a point in quarterstaff. You don't have to put points in hammer, because
the crom faeyr is so good that when you get it you will improve yourself so much that you don't have to be proficient in hammers to have it outclass the other weapons. Since you have ++katana, you should definately get the Celestial fury. Get robe of vecna to improve your spellcasting, you don't need armor. Get the ring of gaxx to go with the robe. When you are fighting undeads, you might want something to protect you from leveldrain, but just get that special necklace I don't know the name to, or get mace of disruption (the upgraded one).
Sidenote:
I found out you don't have to have a crushing weapon to kill claygolems, just as long as you fight on their backs.
About the thief-skills, I think you should get 100 in find traps and open locks, and after that get 70-80 points in hide in shadows and and 70-80 points in set traps. After that you should concentrate on move silently (get it to 80). If you get ring of m... (in Ribald's store...this ring improves these 3 thief-skills by 20) you will be fine. You can also use some thief-items like boot of stealth etc, but then you you won't be able to use good items like boot of speeds etc. Don't worry about stealing, because you can drink potions and steal from anyone you want.
Hope I didn't say too many things you already knew.
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Hmmmmmm...Yes, that must be it