As you know, the novel differed from the FRC1 Ruins of Adventure supplement and the Pool of Radiance CRPG. Where they conflict, the latter sources are popularly (but not unanimously) considered "canon".
Denlor was only a minor character in the Pool of Radiance novel, though he might have been mentioned in passing within the subsequent Pools novels.
Shen, Ren, and Tarl (or whatever their names where) had full NPC writeups somewhere. In fact, I think they had children who also had NPC writeups.
Some city maps of Phlan (and the 4E Monuments of the Ancients stuff) place the Pool where it is located within the novel. Others where it was found in the game.
Tyranthraxus of course had complete writeups in several sources. Porphyris Cadorna and various other "interesting" NPCs also had minor writeups or mentions here and there.
I wanted to get as much information about him as I can compile because I want to use him in the Ruins of Adventure module we are getting ready to start. Instead of him dying though, I wanted to keep him on as a permanent part of OUR Forgotten Realms.