The hospital scene: I feel like it's full of red flags, pointing at creepy worldbuilding rather than solving this crime.
My theory is that the eyes and organs are missing not because they are part of the ritual, but because they are being used as parts by a necromancer working out of the conveniently placed cemetery next door.
This would connect nicely with all the necromancy subplots of BG3, such as
Mayrina's husband, the Necromancy of Thay,
etc.
The main clue in the hospital is the fake beard on the cadaver. A bard elf in disguise, to me, sounds like a Harper caught during an undercover mission.
The other two deaths might be two other Harpers (one at the CRESCENT beach, with the crescent moon being one of the Harper's symbols), and one at Insight Park.
Maybe the Harpers were investigating this mysterious Fel, from the letter, and Fel decided to put a swift end to their snooping.
