The former is apparent in the geth/quarian conflict carrying the theme that only life forms with human-like individuality are valid life, Synthesis carrying the theme that only life forms with organic-like emotions are valid, and the original ending the theme that technology is evil and best completely gone.
I never saw the original ending so can't comment on that, but the other two are wholly wrong. The geth only upgraded because their hive mind turned out to be a horrible strategic weakness and they needed to evolve past that; it had nothing to do with morality. As for Synthesis, it only produced understanding of organics, not identical emotion; EDI doesn't really sound any different in the Synthesis ending than she did prior.
The latter is apparent because in the great majority of all decisions, making the decision that makes you feel good inevitably has the best outcome. Most of the time this is the classically good decision, but ME2 really shows where the priorities lie: the decision at Tali's trial. Withholding the evidence is not, by any means, a "good" decision, but it makes you feel good on the personal level and thus it has the best outcome as a matter of course.
As I've mentioned several times, it's the decision that any IRL lawyer would have to make if they didn't want to get disbarred. In any case, it's not even a particularly good outcome; the best is exposing the court's corruption, and that's either both Paragon/Renegade, or neutral.
I think this is delusional, and I've said so for years. There should be no discernable pattern to the outcomes of decisions if you have no way to predict or influence the outcome. Pragmatic decisions wouldn't be perceived as pragmatic, ever, in reality, if the pragmatic option didn't occasionally have a better outcome when compared to the idealistic one. This applies especially to big decisions since in the smaller ones the outcome is rarely worth the immediate drawbacks of the pragmatic option.
This is because of your utterly false dichotomy between idealism and pragmatism. Renegade decisions are frequently idealistic, primarily ones that involve agreeing with Cerberus and other celebrations of human supremacy, and I've never seen a Paragon decision not based on some degree of pragmatism.
In the only case where an idealistic choice backfires - if you cure the genophage with Wreav in charge - the game hits you over the head with the message that this is a bad idea. Wherever you take a real gamble though, as in curing the genophage at all, the outcome will inevitably favor the idealistic choice, while making pragmatic choices yields no benefit at all but inevitably incurs drawbacks.
Well, curing the genophage is sort of a pragmatic asset to defeating the Reapers, given that it was the whole point of that arc so you could get the turians' help. Beyond that, though, it's not the best decision for the future unless all possible factors are in place (but is of course more helpful with the immediate problem of the Reapers).