Have you run the DRK 30 - 50 and 60 - 70 lines? They explain our mindset quite well.

As an adventurer, we take odd jobs - such as searching bird nests for trinkets and killing anything that attacks us in self-defense. Those birds will kill you - are you just going to let them?

As for our role as the Warrior of Light... if you don't want to do the DRK quests, simply put we acknowledge that sometimes we have to do bad things, like killing people, for good reasons, like liberating oppressed and conquered nations. Nobody said "heroes" are in the most enjoyable or clean of professions.

In regards to Hydaelyn, there has been nothing showing or stating She is anything less than benevolent. However as a goddess She has a very different perspective from us, and likely sees no problem sacrificing a few people to save millions (if not billions). Unpleasant, but necessary.