Hey, I just finished a playthrough with a bitchy Gangrel fem, too. I've never been that rude to the NPCs ingame - got a lot of new lines I've never heard before. It was worth the time.
(Pissing LaCroix and Damsel off is just too much fun! I'll have to do that in TFN, too.)
If you just want the trinket in the haven, you could always use 'noclip' to get inside there. But I don't know about any other code...
"... And the lord set a mark upon Caine lest any finding him should kill him and the mark was ..."