If you haven't been banned yet and you no longer share any of the accounts between you, you should be fine. Item 1 is definitely fine. Just because you multibox from the same home is not a violation. Note that they CAN tell when you're running them in "multibox mode" so do not fall prey to the temptation to do it ever again. I wouldn't worry about that one shammy on his account if nothing has been done yet and you don't plan on sharing it again.

I suppose it is possible that they could ban you by mistake for being used on the same IP but they're familiar enough with family households that have multiple players on the same house LAN that they can spot when someone is doing it within the ToU and when not.

Worst case, go ahead and report yourself from the 2nd shammy account you referenced in point #2 and verify that having two multiboxers on those 5 accounts from the same household is OK. That will get them to go look into the information/data that they have and verify it's all in good order ("Papers, please!" LOL). Then, after they've confirmed things, you can rest easy.