I'm playing with same as you..
Half elf: Fighter/Mage/Thief
And I'm not quite satisfied with it either.
I think i should have dropped the fighter to raise thief and mage faster.
The backstab/set traps skill with thief is something really useful.
On the other hand with the fighter you gain cure light wounds as special skill which is good to keep your game time down (if you care aboute that)
Rest until heald without healingspells take 30 days or something

You also get more hitpoints as fighter but that thing solves later in the game anyway though it might be a hard time in the start.
Tactics, again Backstab and set traps.. a bit boring and coward tactig but it is nessesary to make it singel I think.
So.. The Item thing..
SPOILER
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If you get away to Trademeet as fast as possible you can kill one of the arguing
familis head to get a Elven chainmail, which you can wield and still cast spell.
Another way to get the AC down is to go to Adventurers Mart and bou Bracers of AC 3 but they are expensive.
As you for sure hav noticed you can use both shield and helmet with this multiclass.
Wands is no problem for the mage (except "Wand of the Heavenes" which is only usable by priests)
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