Animal Companions are meat shields. Even when maxed out they need a dedicated healed, essentially needing an Animal Druid IMO. So they aren't a great 3rd action use, and them needing so many feats makes it that much worse. You could make it viable if an animal's part of your concept, but it would take investment, both in your build and in your actions to keep it alive.
Very often you need that 3rd action for movement, but Demoralize (via Intimidate) is a solid hag-themed option, and casting Shield is tactically sound. There are also the metamagic feats which take an action too.
If you want an MCD, you may want to look at Domains/Schools/etc. that have Focus Spells that only take one action, i.e. Force Bolt for Evokers which is a decent choice because it doesn't have a save (which you want to avoid outside your field.) Bard gets the composition Cantrips too, w/ Dirge of Doom (12th via MCD) being a hag-friendly ability, albeit a bit late. Since it lowers saves, it works well with your main spells.
However it goes, stay true to your concept. The math is lenient in PF2, so few choices are risky if you also support your class's main shtick.