Prazipro sounds like a good plan.
If someone gave it to you, that is fine, but double check expiration date. Old already opened medicine may not be so effective.
QT system looks great.
But as always, check ammonia daily, at least for the first week. You never know how well bio filters will work.
Poop is a good sign that they might actually be eating a bit.
The fish might be afraid of you, and start eating a bit once you leave.
I notice in picture the cardinal seems to be hiding in the corner, far from you.
Does it rush to the corner when you come in the room?
If so, tape some dark paper on the front of QT.