So to explain how the server got clue 7: the date the code breakers got for this next hint was 4/3/1982. Obviously American Dad wasn't running that day, however they found that during that date, an episode of Love Boat was being aired (granted, it was a rerun). This relates to those final two emojis in the tweet (the heart and boat). Furthermore the episode had a semi-horror subplot about a phantom bride, further leading them to believe it has to do with HHN. Going back to American Dad, they found that there was an episode called The Vacation Goo that was loosely based off of The Love Boat. In it, the family gets trapped in a cave and resorts to cannibalism, which could be related back to that one speculated house being set in a cave system. The only thing I'm wondering is why Legacy would use the date of a rerun to hint at Love Boat instead of the air date but it honestly does seem like something legacy would do to make it more difficult. Anyways, that's our current thought on this clue.
Thoughts?
Credit to Pots n Pens and werewolv for figuring out the Love Boat rerun date and the connection to American Dad.