Humanitarian isn't really the right word, but it's good advice even if you're not being evil about it. If you have to give out bad news, it's better to be quick and complete about it than have rumors swirling for weeks, or have to keep giving out a new bit of bad news every week for months. That's true even if you're not intentionally being cruel, and can help people process it all at the same time, instead of just living in a deluge of bad feelings.
This is true. I just don't think Machiavelli was well known for his positive humanitarian outlook towards things. I suppose it's assuming bad faith. You do make a good point though, and it's probably better to try and take a positive message out of it.
Are you confusing Machiavelli for Hobbes? Machiavelli was largely a proponent of liberty, and his patrons whom he gifted the Prince, the Medicis, don't even make the top 5 list for inhumane behavior as far as powerful Italian ruling families go.