I don't hate Solas but I did find his romance to be incredibly underwhelming and I've been reading that this could mainly be due to it being tacked in a rush on at the end of development. This is a shame because after finding out who he is (I as the player did, my character still has no clue which annoys me as well because he lied and said everything would be made clear once Corypheus was dead), he deserved something more substantial.
There are three scenes total with him and the last he says he wants to show you how much you mean to him by rearranging your face and then breaking it off. Wha?? If there had been more meaningful interaction prior to that, it would have been carried it much better but as it stood, it just fell flat for me. Solas deserved something a lot more epic than that, IMO.
I also have a really hard time believing that an ancient diety could be so stupid to give a magister darkspawn something as powerful as that orb, regardless of whether or not he just woke up. Also, the whole Vallaslin thing doesn't really sit well with me either. The Dalish have always been nomadic so why are they the ones with the slave markings??? Wouldn't it make a lot more sense for the city dwelling elves to have the markings since they originated from when noble elves marked the lesser classes? That it would be the Dalish left to unwittingly continue to mark themselves as slaves comes across as really disjointed to me at least at this point in time.
Technically, Solas never lies when he says everything will be made clear after Corypheus is gone... it's just that the reveal of who he is and what his real plans were, have yet to occur for Lavellan and hopefully are setting up for something later down the line?
As for the scene where with the Vallaslin, Word of Weekes is that Solas wanted to tell Lavellan about who he was and his unwitting association with Corypheus by giving him the Orb, but he lost his nerve at the last moment and decided to tell her the truth about the Vallasslin instead.
The Vallaslin as slave markings thing kinda makes sense as we know that they cobble together their history from bits and pieces, so the level of knowledge varies from clan to clan. The idea that perhaps they saw depictions of ancient elves or their oral history spoke of their people having markings once, might have inspired them to wear them once more to differentiate themselves from City Elves, unaware of what the actual meaning behind those markings actually was, aside being a representation of their Gods?
It's not like that doesn't happen, how many people get chinese characters tattooed without understanding what those symbols actually mean since they don't speak the language, only to realise later that what they thought meant "courage" actually says "chicken soup"...?
(Although as The Big Bang Theory joked, it takes a degree of courage to show that much love for chicken soup)
It's not their fault that they are so ignorant of this part of their history, the fall of their Empire did happen over 2000 years ago?