You have a point, but Morrigan does say it very clearly before the final battle: "This was what my mother intended when she sent me with you". That line, in my interpretation, shows that even if she was genuinely surprised to be sent away after Ostagar, she knew it was because of the DR.
I agree that she knew when she was sent that her mother wanted her to do the DR. When you ask why her mother sent her then and risked her getting killed instead of having her sent along right before the final battle, she says she doesn’t know and I don’t think that’s unbelievable. Maybe Flemeth thought that the Warden and Alistair would be more likely to do it if they knew Morrigan better or that the pair were going to get themselves killed early on if it weren’t for Morrigan and it would be worth risking losing her next body so as to avoid the Blight devouring the land. Morrigan’s not really the kind of person to make the connection ‘They’ll be more likely to do this because of the personal element’ as even when she tries to manipulate you with that in the DR scene she does really strange ones like ‘Oh, think about the glory!’
Morrie does not really show any compassion at all. She sees Sten and Jowan as top of the evolutionary tree predators and she wants to restore them to that position. As I said when in Cariden's forge you propose she be the first victim she does an immediate about turn...
Branka isn’t proposing that they go off and force anybody to become a golem. Yes, it’s likely that the Anvil will be abused and that will end up happening (and does with Harrowmont w/ Anvil) but there is no point in forcing anyone until people stop volunteering. Morrigan thinks that golems would be useful against the Blight (which they will be) and essential for the dwarves who keep losing ground and haven’t reclaimed any territory from the darkspawn in generations (which is also will be). You can shut her down by threatening to force her into becoming one but she’s hardly suggesting that that be done to anybody.
Also, since Sten and Jowan have managed to be captured and brought down they are clearly no longer showing themselves as the most fit. That she wants to help them anyway because she sees them as strong and can identify with them IS compassion. Also, at the Circle you can talk her down from her ‘the mages let the templars enslave them so why shouldn’t we let them kill them?’ position by pointing out that if it weren’t for Flemeth she’d be in the same position and she’ll agree and stop talking about killing them.
Who says she can't save your life without the OGB? Morrigan doesn't exactly share does she? Fact is, she has knowledge essential to your future and she uses it for her own ends. I think my analogy that she's an opportunistic collaborator and throughly inmoral stands...
Let’s think about this for a moment. Why does killing the Archdemon kill you? Because when the Archdemon dies it’s soul goes into the nearest darkspawn or Grey Warden. It possesses the darkspawn and is reborn and it kills the GW – supposedly destroying their soul in the process – because the GW has a soul and the two can’t coexist. Why does the DR save you? Because the DR pulls the soul of the Archdemon from you and into the zygote. How, aside from the DR, could she possibly save you? The soul has to go somewhere and that can’t be stopped. All Morrigan can do is change where it goes and focus it into her child through the ritual.
Saying ‘Oh, I can help you without getting anything in return but I’m going to force you to give me something in return anyway or else I’ll leave you to die’ is a HORRIBLE analogy for Morrigan’s ‘Oh, I can help you live but the only way to do that is by impregnating me and having the Archdemon’s soul go into that zygote.’
So getting you to do the dirty with Flementh and still not telling you about the fact that you will die when taking down the Archdemon is justified because she's protecting herself... Oh, what about we're all in this together? If you knew she would use you thusly would you take her with you? Again, how do we even know she's protecting herself? Perhaps she's just using you to knock off a rival...
You realize that I’m not even claiming that killing Flemeth is self-defense because we really don’t know for sure (but I believe that it is)? I’m saying that if she knows that you let Flemeth live after Flemeth knows that Morrigan sent you to kill her then it’s not an unreasonable assumption to make that Flemeth will come after Morrigan. Hell, Flemeth herself mentions that very thing before she leaves.
If I knew Morrigan would ask me to kill Flemeth would I take her with me? Of course I would. She’s useful and you only get to the point of being asked to kill Flemeth if you accede to another request she makes to look for the Black Grimoire. If you say no you lose approval but she won’t leave. If you say yes but don’t really look or if you stumble across it you don’t tell her or give it to her then she won’t leave. I think the fact that she only asks you to kill Flemeth once she reads the Grimoire means that she’s found something in there that freaks her out even if she’s lying about what. And I have no problem ‘killing’ Flemeth as even Morrigan tells you she’ll be back and given that Flemeth might decide to take vengeance on you for that lying about that is not really in Morrigan’s best interest.
So using you sexually to conceive a child is OK? I don't agree.
Being a sperm donor is not okay in your world? Okay then. Keep in mind that she’s not raping you. She’s asking you to be her sperm donor which will save your life and you decide whether to do it or not.
Why wouldn't she if she wants the OGB so badly? It's simply retribution in kind, she's taking full advantage of your predicament to use and humiliate you... Do the same back...
Why would you make her beg if you want to live so badly? How in the world is she taking advantage of your predicament and humiliating you? She’s not asking YOU to beg her to save your life, after all.