Weekes has Solas say he hates tea. So Solas hates tea. There's nothing anyone can say that makes this false. If you do, you're just ignoring the story we're all talking about and making up your own fan fiction.
Weekes can show us Solas cares about saving the peasants by showing us "Solas Approves" or "Solas Greatly Approves" or "Solas Slightly Approves" when we as a party do quests that save the peasants... get meat for them, find medicines, find rings, gather supplies. There's nothing you can say that makes this false. If you try to tell us Solas doesn't care, there's the game developer showing us through the game your opinion is wrong.
Now, you can say that it doesn't matter that he cares because he's going to enact a plan about the Veil... that's a legit way to look at the situation.
But it's also legit to say that the developers showing he cares about the peasants is a clue that we don't know everything about his plan for the Veil and that may change how we look at things later on in the story.
Then you take the clue that he cares about the peasants and you match it up with a clue about him saving the world from the Evanuris. Then you take those two clues and match it up with Solas fighting to free slaves. Then you take another clue about the Evanuris fighting Titans and that having dangerous consequences for the world. Then you have another clue where Solas doesn't try to paint himself as a hero at the end of Trespasser, he's wracked with guilt about the elves and other things.
Of course Bioware leaves all these clues, it makes it more interesting in looking forward to DA4.
I'll start by saying that I do agree with your general premise here. BUT I'm reluctant to put such reliance on a game mechanic like approval, particularly since that is contingent on bringing Solas along in the party and completing those quests with him present.
Perhaps the player just speeds though the plot and doesn't do many side quests, or perhaps they don't bring Solas along for whatever reason (I use Dorian as my go-to mage). The limited size of the party, as well as a decent selection of mages (Solas, Dorian, Vivienne, and potentially the player) increases the likelihood that this is the case in any given play.
The same can be said of any sort of banter that might be revealing, whether about Solas or any other character. The player might have had banter troubles, or simply didn't bring along the party makeup to hear whatever revealing banters.
That's not to say that that important or revealing information isn't there, because it is, or that those same things aren't true (Solas approving helping peasants), because they are, but it's entirely reasonable that a player might have certain views of Solas based on what they didn't see and hear in their own game.
I don't think this aspect of it has anything to do with Solas as a character, but with a flaw in the game's design. If PW, or any writer, meant for those clues to be seen and heard to give the character more nuance, then they should have chosen a better delivery device.
I can say the same about any of the banter reveals, particularly those involving Cole reading the followers. Many of those are quite significant, but you wouldn't have heard them in some cases. I know I didn't in my first play because I never brought him anywhere (dealing with squishy rogues is not my thing).
Eh, not really. With how they handled Trespasser and their intentions for it, it actually killed any enthusiasm for both DAI and DA4 for me.
I find this to be very sad. 