Yes, you are right. One get reported, the whole group's going to be checked. Especially if your account is flagged, more likely you're gonna end up with fellow modded and chances for getting reported is high.
I just hope people who use modded APK (especially this one) could be sensible and do not abuse the power they're given to. I know this sounds super hypocritical, but respect other players (including honest cheaters lol). If you really want the prize in FM, try to aim for a tie with other players. Just hope one of them reaches out to you. For House Pride, most likely it was the other House that reported YOUR House because they're being salty their House lost. People who play legally and get banned could still appeal for their accounts, but we can't. Of course the safest way is still, to sit the whole event out by not log in for a few days so you won't get sorted into the group. Though, I don't know if switching your apk with the official one would protect you during these kind of events. Anyone has experience with this?