I am probably the worst person in the world to define squicks, because I hadn't even noticed the rimming. Well, I knew it when I read it, but as for needing identification for it specifically, no, I didn't, not really. I was kinda hoping that they'd spend the night together, because Snape wasn't sleeping very well by himself (dark circles), and having Harry near him can only be an improvement.
You probably guessed it, but here it is: my one squick seems to be: NON-SNARRY. Or snarry that is unsnarrylike -- darkfic that is more torture than any semblance of hope, love, and hurt/comfort. They have enough of the dark stuff in their lives, even without compounding the both of their together.