I'm glad they decided to give Rhode a proper fate, the ***** earned it in my opinion. If you are trying to draw parallels in reality with Rhode, she is a typical fascist who acts first, and asks questions later. She is the opposite of wisdom, and reasoning. The only regret I have about Rhode's fate is that it was not handed to her by the player. Convictions are a good thing, until one becomes blinded by them when the truth is staring you in the face telling you otherwise.
The other thing that bothered me, although this is nit-picking, is that Rhode was discovered inside the tomb, meanwhile you still had to get the helmet, find the orbs, and use the clues to unlock it. It makes zero sense. Why not just stick Rhode OUTSIDE of the tomb turned to stone, and maybe even have her holding one of the orbs you need (giving Bellegar a reason to stone her in the first place being that she might have unlocked the puzzle by chance...) to open the seal? These kinds of errors in logic or continuity upset me more than killing off a minimal supporting cast. Besides I thought the fate of Derk, Dana, and Folo was comical. Now, had they killed off Kevin, then I might be a little angry!
Anyway, going back to the OP's original point, I agree, there was very little relationship development between your character and anyone in the game. Zandalor's character in particular seemed to be the most poorly written. It seemed somewhat generic, and I feel he could have had much more interaction in the story line as opposed to being a glorified cheerleader until FoV where he actually seemed to have a useful role. (At least for Aleroth.) Sure, he "gets" (quite anti-climatically) you the shield, but why not add the obtaining as the shield as another section of content or quest?
Lastly, if Talana was actually Ygerna, when did the takeover occur? It would have been nice to have some history on Talana and her relation to Maxos, Lovis, and Zandalor other than being the last Dragon Knight who you happen to stumble upon as she is dying and passes her mission on to you. Perhaps with enough clues that the most prescient gamer could pick-up before the final cutscene of E.D. that it was actually Ygerna all along.
If Talana was a Dragon Knight, surely Ygerna could have used her just as well as the main character to do her bidding? So I am assuming Ygerna didn't expect Rhode to deliver a deathblow to "Talana" and was forced to make due with a Slayer.
I could go on, and I suppose some of this isn't really that relevant, but I thought I would add my two-cents. Overall I found the game to be one of the better RPGs I've played since Oblivion, and the first game in over a year I've purchased and didn't end up uninstalling a week later. (Previously it was the STALKER series that held that title.) The comedy and sarcasm wasn't too cheesy and had a good delivery. I still feel the story could have been a little more rich though, considering the backbone was there. I understand, this is by far the hardest part of a game to get right. With that being said, a great story can carry otherwise mediocre games, so it is worth the trouble.
Again, it was a fun play-through, well worth the money, and I'll probably play the patched version through once as a warrior, rather than a ranger. I hope Divinity III (You have to clear up what happens to Damian, don't you?) improves on an already solid gameplay, and dedicates a little more energy to enriching the history, characters, and plot of an interesting world.