i have played more thieves than most so i guess i can answer your questions:
1) yes, that's a known bug as far as i know... autosearch makes every other hostile monster to just stand still until you recover from you stun/confusion
2) I have never noticed any increase in shop generation with thieves, once or twice an absurd number of shops were generated (4+ in UD alone) but i didn't remember if i got the two headed calf message when generating the character, and my guess is that i did. Because in the vast majority of games, i didn't find any random shops.
Wins:
Lvl 50 Dark Elf Mindcrafter.
Lvl 50 High Elf Assassin (Dual weilding).
Lvl 50 Dark Elf Paladin.
Lvl 50 Gnomish Assassin (Failed ultra turned normal gate closer)
Lvl 50 Hurthling Thief (ULE).