(If We're Lucky,) Third Time's the Charm (джен)

1: If it weren't mixed, the memorial to the Potters wouldn't need to be hidden.
2: The Goblin Treaty of 1357 is not tied to a canon rebellion. It just ties in with a little incipient plot bunny that is sniffing around in the murky recesses of my brain and currently seems more likely to end up as a dust bunny than a fic. (But we'll see...)
3: I headcanon Snape being fairly proficient in Healers' diagnostics and basic Healing spells and having a large part of the training needed to become a medic, but never having had reason to attempt to certify officially. His own experiences with the Marauders gave him reason to learn, and I can't see him wanting to stay in the infirmary where he'd essentially be a target. Death Eater meetings would have included more than enough incentive to become familiar more esoteric diagnostics and more powerful remedies. Now that he teaches, he's willing to treat his little Snakes so they don't have to run the risks of the infirmary for run of the mill Healing or show weakness outside the House; he can keep (some of) their mortifying experiences private while still getting them the help they need. Snape is not a good person, but this is one thing he can sympathize with.
I also headcanon Slytherin as the 2nd most likely house for abused/neglected children - not because of Black-family type abuse among the DE children who are all but guaranteed to end up in Slytherin, but because abused children have learned to survive however possible. Slytherin gets the worst cases, the ones who have had their ability to trust well and truly broken, who constantly watch their backs and see relationships as transactional alliances. The ones who claim lofty ambitions because power brings its own sort of protection - and there's more than one sort of power. The ones who dare not, or will not (cannot) connect with and rely on others to the extent 'Puffs do, and have convinced themselves that connections are unconscionable weaknesses. Hufflepuff ge