Shield throw is a skill, it’s not cast (much like warpath isn’t cast either).
As for your question, it should be yes to both. It’s basically an autocast, but for the shield throw skill.
Technically, Fireball is a spell, it has the spell tag. That was the distinction I was making. Spells are cast, skills are used. You don’t see nodes on shield throw or warpath saying “When you cast shield throw”, you see “When you use shield throw”.
The term skill means anything that the player can use that goes on the skill bar (including the basic attack). This category is then subdivided into spells (also covering the skills that summon minions I believe) and attacks (which is further subdivided into melee, bow & throwing).
If the term skill referred to not-spells, don’t you think it’s odd that both spells and attacks gain & use skill points? And that the place where you specialise spells is called skill specialisation?
Yes, thats because those are all attacks rather than spells. And attacks scale with attack speed (not skill speed) rather than cast speed.