What companion plot twists did you call on the first run?

Are...you asking which of those listed we called? Or are you pointing out the ones that you called?

Because of that list - I called Anders. And had a weird feeling about Blackwall, but him being a fake was not on my radar.

I've actually called every single character plot twist on my first run of their respective games so far.

I guess I'm too immersed to be judgemental like that during a first PT. I mean, I played these games, as many hours as they are, all the way through with hardly any sleep over a couple days.
To add to the above, I was shocked by:

I was shocked that Anora betrayed the Warden at the Castle. I was shocked the Ultimate Sacrifice was a thing.

I was shocked when I came home from the Deep Roads to find Bethany going to the Circle. I was shocked when Leandra turned into Frankenstein. I was shocked and browbeaten by Anders into capitulating to his gaslighting demands about getting ingredients and going to the Chantry. I was shocked when I asked Fenris to change his mind about siding with Meredith--and he didn't. And I killed him. So shocked, in fact, that I reloaded to try different dialogue options and realized, sadly, that he was doomed to die that game. I definitely held my breath while Cullen and the other Templars considered attacking.

I was startled that the celebration party turned into an attack. I was worried when I went out to face Corypheus and his dragon alone. I was touched by the cheesy song. I was shocked by Leliana MURDERING A NUN. I was disappointed to find out I/Inky wasn't the chosen of Andraste, because I was half believing by then. I was at wits end about Morrigan being an outright liar and running off to go kill the guard of the Well. I was worried when Keiran ran off into the Fade. I was surprised when I learned that Inky was under a geas from Mythall- that Flemth was Mythall. I was shocked by the sudden disappointing finall battle with Cory considering how epic the Arbor Wilds sequence had been. I was actually pretty whatever about Solas leaving. He's my friend, I don't control him, so I found it weird that Leliana was sending out scouts to look for him, that crazy ass nutcracker. I was very surprised to find the original Inquisitor held in a time spell. I was severely irritated to learn about Titans. I was shocked and supremely irritated to learn that the writers had made my Inky into a controlling asshole in the time jump. I was pleasantly surprised Mother Giselle apologized about Dorian. I was shocked in the BEST way when Cullen proposed! And I was honestly confused, worried, and doubting about Solas when the Qunari Leader started trash talking him. I wanted to believe in his goodness, because he'd been a good friend in base game. But by the time I really understood what he was doing, planning to do, my hand was killing me and I just wanted to live.

And then I was shocked to find out I only had one arm.

I guess these games are made for me, Miss Oblivious

Other than that there were no plot twists I didn't know about already. I generally don't play games when they just came out (I can never afford a 60 dollar game) so I have to wait until they're on sale and by then the internet is full of spoilers.

I called the plot twist that I would fall in love with Anders and never find fault with anything he did ever.

I get severely spoiled with these games. I have no willpower The events of the battle at ostagar surprised me, I hadnt spoiled myself yet. Blackwall I think I wasn't spoiled but it didnt come as much of a surprise when he was revealed. I had found a few things odd, especially that he wasnt affected by the calling.

all to be honest, the most obvious were Morrigan and Blackwall.

Blackwall was a fucking joke to be honest.

At least once, when Cassandra asks him why did he decide to join.

Yeah I'm not suer I remember exactly whether I called whether any of them. I was suspicous of one or 2 like what is Anders up to? When he was making that bomb for the chantry that was. Also to the same extent Blackwall  too. I don't think I was suspicious of Morrigan and when not playing a mage myself in those early levels I find her magic useful but I don' t remember thinking anything specific about Morrigan but then I didn't really fully understand the lore when I first played DAO because like with the mechanics I struggled to undrestand it all it was only when I started to understand the mechanics when things started to click.

At what point does a lie of omission turn into something that is simply not your business?

I literally just gave you an example where it isn't. You can't say "all".

And would always lying by omission suddenly make Solas innocent?