And as for the Dalsih Inquisitor not having the necessary training or knowledge before, after they drink they will so that argument is rather Morrigan biased.
Uhmmm... no. Just because one has information does not mean one has context to use or interpret that information. A good example of this is Phil Coulson and Project Guest House, or Commander Shepard and the Eden Prime Beacon.
In Shepard's case she gained the information, but couldn't truly interpret the images until she got the Cypher, which provided context.
Spoiler for AoS:
A Dalish IQ, especially a non mage, wouldn't have the training and context.
And this is where we hear but Morrigan...!
Flemeth herself tells Morrigan that she is driven to preserve things like the Old God Soul and the Well, because that is what Flemeth raised her to do. This is a fact. Not subtext, Flemeth says it straight out. So if this is the case, what makes you think that she didn't provide Morrigan training so she could do what Flemeth meant her to? Do you honestly think Flemeth had Morrigan knitting the entire time they lived in the Wilds?
And as for shapeshifting into a dragon... Huh? Morrigan is already a shapeshifter, she has an affinity for this kind of magic already. And while we're on the subject of affinities, why wouldn't any of Flemeth's daughters have one for the shape of a dragon? I don't see any reason why that quirk wouldn't pass on, especially if they have the knowledge and already are able to shapeshift into other forms.
What we know about Morrigan is she was raised by one of the most powerful mages in Thedas, is a talented mage in her own right as well as a shapeshifter. She didn't truly leave the Wilds until the Blight and may or may or may not have gained the soul of an Old God and had a son. She restored an Eluvian in the two years after the Blight, then left Thedas for the Crossroads. After spending several years with access to portals that could take her all across Thedas and beyond that, she returns and becomes an advisor to Celene.
Does anyone honestly believe the woman sat around eating grapes and having her hair done during all that time? Didn't think so.
Morrigan is far from perfect. She's catty, arrogant, obnoxious, sometimes selfish, and hard. But there is a person under it all.
And yes she's Flemeth's daughter, which is not something you can discount, especially since it gives her access to a very powerful and knowledgable teacher.
Remember, Flemeth wanted her to have that tome. And she prepared an out, expecting Morrigan to try and kill her, because that was how Morrigan was made. It's all over the conversations with Flemeth if you look.