Blunt and Nasty or Clear and Edgy?

I was being trained by my MTS apprentice the other day and he reminded me that I'm not the best at saying things clearly and concretely and simply (I have other superpowers). More than that, he stressed the importance of sometimes being blunt and putting stuff out there, especially when speaking from the front.

I think he's got a good point. The hangups I have about being blunt are:

1) I really don't like it when this is the only weapon a church leader has in his arsenal. The church aren't doing what I want so I'll tell them off publically (or maybe run a training course...).

2) I think that if this is used too often, and other things aren't also done then the bluntness ends up being discouraging.

3) I don't want to come across as a leader who's angry.