Yeah, I wasn't exactly glad to hear that from Solas either. All BW did was give the trolls more ammuntion. 
As for the removing/keeping the vallaslin, what I did was think about how regardless of what the original meaning behind the vallaslin was, the meaning is different now and part of who my Inquisitor is as a person. I was tempted to let Solas remove the vallaslin, but the vallaslin is one of the defining characteristics of the Dalish. If my Inquisitor lost that, she'd have less of a connection to her clan and her past life.
I have no idea if it was mentioned in Masked Empire, but if it was, I'm pretty sure that it wouldn't have just been the trolls that said that Arlathan was a slavery empire.
Honestly, the same could be said about the Dalish- and often has. Just like the vallaslin revelation, it just gives the trolls more ammuntion. 
And that's weird. They didn't call my Inquisitor shem'len. How did you go about moving through the Temple? I wouldn't be surprised if that had a hand in it.
I decided to do the rituals, despite Sera's whining about rituals being 'bad' and Blackwall saying that we needed to hurry because the Inquisition soldiers were fighting and dying. I was also fairly polite to Abelas.
I’d like to note again, Solas/Fen’Harel is
hardly an unbiased source, being the god of
rebellion and all. Taking him at face value on everything it’s pretty much like believing that a libertarian point of view of the Circle of Magi as the absolute truth. Besides, what the blood writing
was in the Ancient days doesn’t change what it
is today: a symbol of defiance, cultural identity, pride in heritage and perseverance in keeping a lore long forgotten.
As for the trolls, Gamer, I think it went both ways. BioWare has given us plenty ammunition too in regards of the Chantry, I mean… there were some common statements that certain trolls preached (not citing names, If you’re curious PM me) in pre-release talks:
1. The Inquisition is not going to be independent from the Chantry, as the latter is “funding the bloody thing”.
2. The game is not going to allow radical change, the end to the Mage-Templar will be regional, neither institution will likely be disbanded, regardless of who you side with.
3. Lord Seeker Lambert was the only sane person in Asunder (lol, can’t keep myself from laughing at this one). Trying to keep the cure from Tranquility from leaking in such a volatile situation.
4. The Inquisition is a specialized order, and like many of those, is going to be disbanded once the problem is solved.
Yet, what we have:
1. The Inquisition(mostly, if you disconsider noble donations) funds itself. Which is evident in the constant “Gather Coin” operations in the War Table. In fact, during the whole plot of the game, the Chantry is going on a steady downhill. Without a clear sucession it’s deadlocked, and this deadlock is crumbling the organization, if it wasn’t for the Inquisition supporting a Divine candidate, the Chantry would probably wouldn’t survive, schisms would have been inevitable. In this situation the Chantry is not in any state about funding a paramilitary organization, they are too preoccupied pulling themselves back togheter.
2. If you side with the mages, between the Templars who join Corypheus and are crushed in the Arbor Wilds, the Seekers who follow Lucius in joining the crazy nihilistic cult and the sane ones who drop their flags and join the Inquisition… I think its pretty safe to assume that in this scenario the Templar Order and the Seekers of Truth as we knew them are gone. Comb that with a Leliana who was made Divine, and the Circle of Magi, as we knew it, is also dissolved. I have to admit that I rather like that outcome, let’s try things in a different way, let the Inquisition remain as the much needed
secular organization responsible for dealing with magical problems.
3. After doing Cassandra’s personal quest: turns out that Lambert was acting with his own motivations all along, keeping the cure a secret was more in line with preserving the Seekers dirty secret than any political backlash that could have resulted from revealing it to the Mages, this was just so
delicious that I felt an urge to break out fom my media blackout just to make a troll thread on this, sadly, I’m too polite for that. Also, in this same quest, it was also refreshing to see that even the supposed incorruptible Seekers sell their own to demons and go off to join crazy cults, glad to see that one doesn’t need a staff and a robe for that.
4. If the narrated epilogue by Morrigan doesn’t end up retconned like the ones in Origins/Awakening than at the end of the game the Inquisition is among the most powerful and influential players in Southern Thedas, hardly disbanding.
Seeing this for me was so good that I can live with the ancient elves being potentially jerks.