You pose an interesting question about boosts and editing by the original poster.
One way to look at it is the trust you feel between yourself and the person whose post you boost. Boosting random posters' toots may be more problematic than boosting posts from those who are better known to you and less likely to twist their views in a perverse way.
Boosting friends or trusted news sources is more sensible than boosting a random person's work.
Read people's timelines...be safe.