Yes, but the levy pikemen come with poor morale, so if you manage to rout one or two, preferably at the flanks, their whole line will collapse and rout, even without making contact with your troops.
As for the cavalry, it may be a version thing, I´m playing with 1.2 and I never noticed such a thing. And I do use Equites to rear-attack phalanxes. To let them slug it out is taking a fifty-fifty chance: If the phalanx keeps fighting the infantry, they´ll be fine, mostly. They´ll still loose some men, because the phalanx men aren´t that stupid not to realise that there´s someone poking spears into their backs. If they turn, however, they´ll cut a lot of your horsemen down in the swipe, but they´ll get slaughtered by the infantry in their back. They´ll be dead one way or the other, it´s just the number of men you´ll loose that´s a bit unpredictable.
Plus, the melee skills of the roman cavalry aren´t awe-inspiring, to get the best out of them you should rather use what charge bonus they get. At least that´s my opinion.