As a crewing bod, I find this job is as easy and hassle free as you make it.
There will always be a few idiots in every single airline, that no matter what change you give them, it will be unfair and unreasonable.
On the other hand, if you speak to people as you wish to be spoken to yourself, you will find your job a whole lot more enjoyable. When a crew member questions the change, as long as you have the knowledge and tact to give them the GENUINE reasons, they will respect you that much more for it, even if it's not what they really want to hear.
Those that really kick off can go and speak to the cabin staff manager or CP, im not here to take sh1t from crews who wont or dont want to listen.
And if crews do favours for you, dont forget it. They certainly ( and quite rightly) wont, and it will only come back and bite you in the @rse if you play dumb!!!!