It is easy to blind one's self to the reality, as is the case with your IL's. Although you may express doubts and doubts in and of themselves are not disfellowshippable (is that a word?), there are, almost inevitably, members of the bodies of elders that will not be able to discern doubt from apostasy. So, be careful when expressing anything with them.
I heard of a case where a brother just lost all religious perspective. Issues in his life affected his faith in everything to the point where he simply did not believe anymore in anything. He told the elders he no longer believed. Some wanted him out. Others felt compassion for him, cause they knew of his situation. He wasn't a threat to anyone. He kept to himself. Didn't communicate with anyone really. Still, there was this almost vehement desire to see him ousted by a number of the body. Is agnosticism apostasy? I doubt it. The moral of the story.....fading is safer than speaking.