I have several qualms with Loghain. I understand that war demands sacrifice, but I also believe as much as can be done to limit that sacrifice should be done. Word of God, as we're calling it, has also stated that Loghain wanted his men and/or Uldred in the tower in order to prevent the signal from being lit. This alludes to the idea that he had a carefully laid out plan to betray Cailan and walk away from it without having to bear the responsibility of that action. The defense of that action usually hinges on him preserving the army. My problem with this is that during the entire course of the game (is it not 2 years?) Loghain does all but nothing with this army to stem the tide of the Blight. I understand this is a game mechanic, but still. If the horde was massively bigger than he expected and he turned his army away to preserve it as a defense, then he should have realized that the darkspawn were a threat and began taking steps to utilize that army. The only thing I recall is seeing a handful of men trying to contact the dwarfs.
I would also be more lenient with Loghain if he didn't tell such blatant lies. I assume that many of the Banns are not new to war; they would, perhaps, understand if Loghain explained that they were suddenly overwhelmed by an unexpectedly huge horde and fled to preserve the army. But no, he touts that the wardens betrayed the king, simply to discredit and avoid blame.
The poisoning of Arl Eamon and, I believe, the partnership with Howe also occurred before Ostagar. Clearly, Loghain was planning some sort of treason against King Cailan, violent or otherwise. In my opinion, the most probably and evidenced motive for this is Anora's position being jeopardized. We find out that, shortly before the events of Ostagar, Cailan and Loghain had an argument about something "the queen did or didn't do." The only evidence we have of difficulty between Anora and Cailan is that she didn't conceive an heir. Perhaps it can be blamed on Cailan's consideration of allying with Orlais, but even so, it is not a general's position to dictate whom a king forms alliances with. Furthermore, it's not unheard of in the real world for newly independent nations to ally with much stronger ones against a common goal without being completely overrun.
Now that I've mentioned Anora, I must ask: if she was really ruling for five years and was so competent then why did Loghain step in as reagent? Why not continue acting as general, and perhaps advisor, and let Anora rule on her own? We know from the Landsmeet that a woman can rule as queen on her own, so Loghain instituting himself as essentially king appears to be nothing short of a power play.
Wow.. long post. D= Sorry; I'll get to the point. Loghain's behavior is categorized by shady activity: planned treason, lies, and a power play against his own daughter. While I understand some of what he did, as a warden I usually don't invite him into our order if for no other reason than I could never trust him. Riordan says that you can't stop being a warden, but Alistair turns and does just that. If the player warden is evidence of anything, it's that being a warden doesn't keep you out of politics- Loghain could still prove disastrous. I would reconsider (and love) if there were an option to spare him on the condition that he allocute to everything he did in front of the Landsmeet, but alas, no such option.
As for Alistair, I always felt guilty having him do the sacrifice. However, he IS the senior warden, so it should technically fall to him. Furthermore, his little Landsmeet temper makes me question both his abilities as king and his abilities as the warden commander rebuilding the order. Dark ritual ftw!