Let's hope the crashing problem was a local problem of your install. Thank you for finishing the quest and your feedback! The three sirenes are the original ones, and their turning hostile is original behaviour as well. I wouldn't like to interfere too much into the original game, although I understand your suggestion about not wanting to fight the three sirenes.
NPC interjections is a good idea, although it goes further than the bugfixing / issue solving of the original mod I volunteered to do. I am not saying I wouldn't like to include those, I am just not sure I am allowed to expand it. I have to say I like the suggestions about Jaheira and Safana making comments, though.