does story makes sense without incest patch?
Actually this one might make
more sense without the patch:
1) stories that have a sister you've been living with all of a sudden need you are hard enough to believe, having 2 of them really stretching credulity. Not to mention the "mom" crushing on you.
2) The intro without the patch says your mother died and this is part of why your father is so distant. So, step family, actually helps move the story from that line of thinking too.
3) no other real changes. No weird "landlady" text to worry about.
As far as I can tell, just use the patch if you want that extra taboo story element. If someone has identified another place it has an effect, I'd love to hear it.