Cloud and Squall posted...
That's true, but that's kind of overestimating Voldemort (and the ministry for that matter. Sirius didn't have a Dark Mark, and off to Azkaban he went. I'm guessing it's not common knowledge or something)
The ministry are idiots--Sirius went to Azkaban without a trial, for instance. (And furthermore, wouldn't it sew more discord if you were suspicious of everyone, even people who didn't have dark marks? It'd fit Voldemort "his gift for sewing discord is very great").
Or at least leave a basilisk fang in the will. "For defeating the monster, a keepsake"
Now that I think about it, that's actually not possible--Dumbledore is not a Parselmouth--he can't open the chamber.
True, but Dumbledore chooses to send Snape after Quirrell and not McGonnigal.
To keep an eye on him, yes. But that makes sense, seeing as Snape is a known former Voldemort supporter.
I...don't follow the logic; why would being a former death eater make Snape a better candidate to tail Quirrell? I read it more as "Dumbledore trusts Snape more completely due to love."
--
Cats land on their feet. Toast lands peanut butter side down. A cat with toast strapped to its back will hover above the ground in a state of quantum indecision