Some choices do not really have Light, Grey, or Dark options, such as deciding what order to find the Star Maps in. In some cases, Light, Grey, or Dark are not clear, such as deciding whether or not to aid the GenoHaradan. However, keep note that it is not always clear. On the opposite of that, any choices that are mean and cruel will result in Dark Side points affecting your alignment.

Whatever choices seem benevolent, and super nice, then they are almost always 'light'. Though there are several choices to make in both KOTOR I and II that don't affect the endings, and whether you're playing through as dark, light, or even gray, the choices available are fairly easy to distinguish between dark, light and gray. Non plot-moving sidequests and minigames that are not required to complete the game have ambiguous status regarding canon. Canonically, the Light Side endings are supported by statements from LucasFilm and are made reference by other sources, but each individual choice is still left ambiguous and left to the decision of the players.

No, as there is no detailed definition of canon choices officially.

Kotor genoharadan light side