The "hell" of the Apostles' Creed is Sheol, the abode of the righteous dead before Christ's coming. It's not the hell of the damned and the fallen angels.
The Latin -- the Apostles' Creed is originally the Roman baptismal creed -- makes this clear. It says that Christ descended ad infernum -- "to the depths" or "to the lower regions". No implication that he went to save the damned.
Aquinas had nothing to do with the "selling" of indulgences.
There's no Protestant seminary on earth that will give you a fair and unbiased view of Catholicism, just like there's no GM dealership that will give you a fair and unbiased view of Fords or Toyotas.
Aquinas did, in fact, endorse the selling of indulgences. IN fact, his own writings (look them up - they are available fairly easily) demonstrate not only an endorsement of the practice, but expended the doctrine to recognize indulgences as effective not only for the living, but for the dead...
So, by his dogma, you could actually “buy” indulgences for your dead father or brother - and shorten their time in Purgatory...
Catholic historians have done much to rewrite history. This isn’t just from a “Protestant” view. A simple study of the remaining writings of early church fathers through current day will demonstrate an historical record (official from the Church) that does not necessarily reflect the reality.
Please read for yourself. Taking Catholic (or Baptist, or Methodist, or Lutheran, or any other for that matter) history or teachings without going to the source is asking to be lead astray.
As a Pastor, I strongly encourage my congregation to not just take what I preach as the “Gospel Truth”, but to go back and read and pray on sermons themselves. This is a huge part of why the Roman Church was so adamantly against common-language translations for centuries (and why early translators were excommunicated and some even burned at the stake). But Catholic History conveniently disregards that chapter in church history as well.
And don’t get me wrong - while I am “Baptist” in my faith and practice, I do not take everything I read and hear about Baptist history or any other teachings without digging in other sources. I am after truth.