Huh. My initial reaction was identical to kalalala's: he'd love his child regardless, but things would probably be easier if the child's mother was also a mage. The end.
But Cerulione has me thinking: there's rather a lot more to it than that, isn't there? What will the Circles look like in ten or fifteen years' time? That would have a tremendous impact on the experiences of an IQ/Cullen/mage kid family.
I approach it immediately from the POV of my canon mage Trevelyan; she didn't have any particular grudge against the Circle (it helped that, like Vivienne, she was privileged) and would not have an issue sending her child there. But what if the IQ was Dalish? I'm not sure whether Cullen would really be on board with attempting to hide his child's abilities.
Hmm... IMO, in my own world states I always help the mage & ally them, they finish up making the College of Enchanter with Leliana backing them up IIRC. So it's likely to be more free than most Circles before Rebellion. And even in Mage Trevelyan PT I got the option to tell Josie that I see my families often & can go home in the week end or things like that. It's kinda like a boarding school.
I don't say Cullen won't love his mage kids, it's just that I feel he would want to "do the right thing" in the name of love. There's this side of him I really feel.
My Dalish Inquisitor won't agree sending one of her kids to the Circle tho... We've stories of families like the Hawke who managed well despite everything.
That's what we thought as well. Although we also thought that he would be even more protective of them when compared to a child without any magical talents. Ti also thought that he would be pretty much be reminding the child or children of their gift's danger. Then I was like my mage would probably just be facepalming in the background since she would find it cute, but she would be just as protective as he was and she could actually teach that child or their children to master their gifts.
I know my mage would have an awkward laugh and be like. "Yeah...no." She loved to study and the Circle System in general, but she did have a good experience with those around her; plus she did not love the feeling of being constantly watched and judged. So I think my mage would probably be against sending their child or children to the Circle, unless she and Cullen could constantly check up on them and know that Circle is top of the line.
I can imagine Cullen wanting to send the mage kid to a Circle/anything like that in the reasoning that it's for the kid's best, for him/her learning to harness their power properly etc. Cullen was a Templar, he must've seen many hedge mage/apostates doing bad things unintentionally because they never learn to master their power properly, or because they're afraid etc.
Imagine a non-mage Inquisitor? There's magic in Trevelyan bloodline. And a non-mage Lavellan can also get mage kids.