I think philpott is a lot of things, stupid, anti women, violent, self centered, controlling, greedy but ... I don't see him as evil. except for stabbing a previous partner, that was evil.
He planned something stupid to get himself another house, planned to make himself a hero, and like many arsonists things went out of his control.
His reaction to this is beyond my comprehension, you'd have thought he would die in the attempt to save his children having put them in such peril, so he's cowardly as well.
His wife was easily contolled by him but you'd think even she would baulk at setting fire to the house with the kids in it. But controlling partners are all too common.
He deserves his punishment, but I don't see violence is the answer.
Also I thing the welfare question is fair given his brazeness in wanting the state to support his tribe.