Well, here's my take on the whole Paladin vs. Evil discussion. If you intend to waste all the Temple denizens anyway, and you are only playing a role/ruse to gain intelligence about the temple infrastructure, then I don't see a problem with the Temple quests. The Temple quests do provide intelligence after all and little benefit to the Temple folks if you're killing all of them. Finally, the AI does not facilitate the defense the Temple would put up if you simply started slaughtering everybody. For example, the Earth Temple Troops could put up quite a fight if they worked together, but they don't. To me, it seems less realistic that they stand waiting for you to visit destruction upon them when you feel like it rather than mounting a viable defense...my two cents.
Lying (even to Evil people you intend to kill later) goes against a paladin's code of honour, helping evil people (even to tie thier shoes) also goes against a paladin's code of honour.
I think a paladin could take certain actions that were designed to assist Evil to destroy itself, but it would be in a very narrow range. Even things like framing an evil guy while eradicating another evil guy, while dealing an additional blow to evil, would surely violate a paladin's code and personal ethic of lawfulness.
Neutral Good, at the very least. There's no way any lawfully aligned person would frame somebody. That's illegal!
Ahhh, but what constitutes 'illegal' inside the T of EE? They operate according to a very chaotic framework of backstabbing and treachery, which they would be aware Iuz probably knows all about. But no, a paladin still wouldn't do it