Agreed on both points, and I should have noted that the "pack" would have to buy into the objectives of the wider conspiracy for the (hypothetical) scheme to be plausible. A couple of responses to your second point: we don't know how many life insurance schemes may have succeeded, and this may be the organization's first try. I think the scheme had spun out of control sometime after Charles was murdered and then it was indeed true that the murder of the children didn't make sense in the context of the (hypothetical) scheme. To use another tradecraft term, Lori had "left the reservation." Her fear of being exposed as a participant in Charles's murder and her vicious desire to hurt the Woodcocks caused her to initiate a wholly unnecessary tragedy.
Let's not forget that, were it not for the missing JJ, it is likely that they could have gotten away with everything. Tammy's death would not have been investigated, Alex would have but it was natural causes. I definitely think that killing the kids was a huge mistake. Obviously it's evil. But it was also a huge operational mistake regardless of whether this is a broader conspiracy or if it was just Lori and Chad operation to live happily ever after together.
Like the 60 burner phones, there were a lot of indicators of broader involvement early on (January threads) that many of us looked into and found some interesting connections but nothing solid.