I regards to "proposing under false pretenses - while she thinks he is something he isn't and doesn't have all the facts and is unable to make an informed decision" I can completely understand this argument, as I said above, but I think it is not as bad as you make out. Proposing as Clark and hiding Superman is like not telling someone you are a devout Catholic until after the proposal. Clark's personality - the man she loves - is no different whether she knows or not. He's still the same man.
I am not sure your analogy really makes sense. I think your point does. In "Metallo" Lois admits that Clark is essentially the same in his being and goals and actions as Superman. She might not know both men are the same, but she knows the key things that motivate and inspire them.
On the other hand, being Superman is a big time commitment. So she really should have a right to chose if she is willing to have a husband who she has to share with the world. I guess you could argue being a top-notch investigative reporter means he has to run off at all hours of the day and night to, so maybe even that is not as big an issue.
I did realize something else about Man of Steel though. In previous incarnations Lois always finds out sometime after becoming romantically linked with Clark and or Superman. Revealing his secret will inevitably expose her to some scrutiny. In MoS despite her "my mystery man" line to Woodburn, Lois and Clark do not have any substantial romantic connection when she decides not to tell. For the first time she makes the decision to keep his secret without really having her personal feelings tied up in it.
