Seals involve wards, so they wouldn't be able to sense the spirit but they would be able to sense the wards, so they'd definitely be curious about what they're for and what's in there.

They weren't all watching (there's just a council in charge of it, we promise y'all weren't on some kind of messed up reality TV show).

The familiars can go/appear as they please since they're linked to the character, so they can appear wherever. The fountain can't bring people back to life or change species, it would just heal injuries. So like a zombie would just become a hella fresh unsmelly zombie.