The jealousy comment never bothered me that much considering when you take Fenris into the fade he is tempted by the demon's offer. There's obviously some lines when it come to magic that Fenris is willing to cross.
I have some issues with the Fade stuff, tbh. It bugged me that some potentially interesting stuff gets brought up, and then it's just dropped after one tiny conversation (*sigh* I really wish they had taken more time with DA2, it could have been so much more. I love it, but there's definite some stuff that suffered with the omg release now!).
Every one of your companions will betray you. Anders is the exception since it's not Anders, it's Justice (and Sebastian, but that's because he refused to go). Some people have screamed about how that makes Fenris a hypocrite, but I think it also points out that
everyonecan be tempted, and doesn't that kind of back up his point? The demons use some deeply personal ****, too. For someone who has spent his life under the power of others, being equal to that and being able to fight back would be tempting.
And I don't think Fenris tries turning anyone over to the Templars. He might suggest the mages belong in a Circle, but he doesn't turn on his companions that I can remember...
Nope, and there's a banter between him and Sebastian where he says he won't hand Merrill or Anders over.
Sebastian: It's our duty to tell the templars.
Fenris: Then why haven't you done it?
Sebastian: I guess I was hoping they'd come to it on their own.
Fenris: And then you wouldn't have to betray Hawke's friends, right?
Sebastian: That's not reason enough to allow a maleficar to walk free.
Sebastian: Which of us should do it? Shall we draw lots?
Fenris: Uh-uh. You want to turn them in, you work it out with Hawke.
The jealousy comment makes no sense whatsoever either, though. Uhm, hello? Amnesia? Fenris didn't even know he had a sister, let alone that she is a mage. Anders is just full of ****.
I think there's a couple of vague references to it, but not directly with Anders. And there's no way Fenris would be that open with someone he doesn't like or trust (all though if you take Anders for Bitter Pill, he would have heard Hadriana tell Fenris about her). It's just flat out spiteful and an attempt to reduce Fenris's experience to nothing (again). Because there's no reason ever for anyone to be afraid of magic or the people who wield it, and it's only an isolated thing.
yet he freaks out cause Fenris likes to rip out the hearts of selfish/evil people once in a while....
This is where I'm totally happy calling hypocrisy. Isabela's a pirate, and Varric's probably done some shady **** dealing with the Merchant's Guild. Hell, Hawke has killed people for money (and if you take the Red Iron path, probably more than a few). But that's totally cool. Being in a position where you can't say no make you the worst person ever.

....
no...

Spoilers for Dissent, just in case