Simply adopt the attitude that they will of course keep their players in line, and they will speak to you only at appropriate times, and that clearly there will be no dissent - as per every other game you referee.
Why make them think that you are either
a)used to getting a lot of flack for poor decisions
b)worried about this game in particular
Any hint of a problem - call them over and read the riot act - "behaviour is completely out of order, not sure what standards of behaviour are normal for you but I am not used to this... get it sorted, NOW. Back 10 - PK against you for xxxxx!"
Any "shenanigans" ping it immediately, be a b'stard - don't play any advantage until they twig that you are not messing about, then you can try to get a game going - IF they are willing.
By shenanigans, I mean any little silly niggles - 9s pushing each other at the scrum - if the one pushed was in front of the ball ping him then reverse it for the push - peferably ping the one who was offside before he gets pushed. Just play ZERO tolerance to start with. You award a PK the offenders must retreat 10m rapidly NOW, RUN! They may not interfere with the ball - if they do the it's +10, but rather than try to go quick call captain over tell him what they did wrong, tell him that future misbehaviour limits your options. Then make the mark.
Any repeat = YC, no more mr nice guy.
Forget the crowd - the ones who catcall are morons whose opinion is not worth the air they wasted breathing while they said it.