Students of all ages recognize (and usually resent) disingenuousness. Don't try to be someone you are not. It's certainly important, as this module suggests, to build relationships with your students, but it doesn't end with a "What's new?" at the door.
I tell my students (middle school) that my classroom is my playground, and I'm going to have fun whether they do or not. Some of them do find that a bit off-putting, their teacher taking an altogether different approach than what they're used to. But most end up learning a lot in class, and are eager to be there because they never know what Mr. Cohen is going to say or do next.
I can't be that dry, stick-to-the-curriculum-the-way-it's-written teacher. So when I teach about gravity, I ask the students to consider this situation: an aide in our building (he weighs 300+ pounds) and a specific teacher (she can't weigh much more than 100) are on the roof. There's padding below, so they won't get hurt. they jump at the same time -- who lands first? I'm thinking this is not the way most people broach the topic, but my students get it pretty quickly, and have that means for remembering it discussed in the module.
Having said that, I know my style wouldn't work for everybody. I wouldn't even suggest that anybody try it, to the point I've resisted chances to this point to have a student teacher because, from a technical standpoint, mine might be more the "How not to" method.
But during any class, it's firmly established who's in charge and what we're there for. You need to establish a rapport with each student to be sure, but you almost much inject a lot of yourself into each session.
I always say if I'm worn out -- physcially and emotionally -- at the end of the school day, then I must have done my job well that day.