Here ya go @CuriousCaitian https://www.roddenberry.com/media/vault/TNG-WritersDirectorsGuide.pdf - that's the original and first revision versions.
I have the fifth season revised edition, which I tried to link a couple relevant pages to above - reveals a lot of what Gene was thinking when he created the characters. I try to upload the few relvaent pages again later, which makes for an interesting comparison for what Gene says regarding Deanna and Guinan.
Thank you! Guess that answers my bible question, huh?

Downloaded, and will be eagerly devoured. Insight into what Gene was thinking, rather than what other people think he was thinking, is very welcome indeed.
The evolution of the Troi character is interesting, from Chief Psychiatrist and working in the medical department to occupying the chair beside Picard (originally where Data was going to go as the 'Captain's Advisor') as they realised that giving her the chair made her more prominent and gave her more to do. Granted, the writers still didn't have a clue and she was at risk of being axed at the end of S1.
The episodic nature of TNG would only hamper the role of a counsellor, as the hardships of a particular mission or incident would disappear by the start of the next episode (Picard's dealing with being assimilated is the only exception, but Geordi being abducted by Romulans and brainwashed into being an assassin is fine the following week, likewise the fact the Picard thought there were five lights). Without the commitment to show exactly how she helps them with the stresses and strains of life in space all we get are "emotional issue of the week" (not necessarily always featuring the main cast), which again are magically cured in less than seven days.
Bolting on lots of other things for her to do makes sense, as it bulks up how she can be used, though does make her role somewhat amorphous and ill-defined. Had they just settled on something like Comms/Cultural Officer, she could man a bridge station, deal with language/translation issues, as well as be a font of knowledge about sociology and psychology of alien races, their cultures and practices, making her a valuable asset on away missions or on the bridge--whilst her empathic abilities could be put to use during first contacts and diplomatic forays.
However, she probably would've just been reduced to saying "hailing frequencies open".
A neat summation of the issues, and I can't help thinking the original concept might have been the better one, if, as you note, still not ideal for an episodic series. I really like your alternative suggestion, too; combine that with @Orphalesion's ideas, and you'd have a pretty strong character, I'd say.

All this is making me wonder, not for the first time, what a serialised TNG, or TNG-style series, would have been like. I guess a not-inconsiderable part of my discontent with current Trek series is I had hopes for such a thing, and they didn't pan out (in my opinion). Maybe if JMS's pitch had been accepted, and of course we don't know what else is planned by Kurtzman.