MI first off, do it your way. I can't work off someone else's notes although I might nick the best of them and assimilate them in to mine...(suitably referenced....) secondly, the students have to take responsibility for their own learning. If they haven't done the prep....well, I would send the out actually. Then do lots of small group work after you've delivered a bit...there will be some knowledge in the room already. Don't take the laughing personally. My foundation degree students are really badly behaved. I ignor it and concentrate on being charismatic and fun. The ones who don't work and keep looking at their phones soon come to heel, because they realise they're missing out.
Feel free to tell me I don't know what I'm taking about...I'm sure I haven't got the whole picture and of course I don't know your area of expertise at all but my teaching epiphany came when I handed over the responsibility for learning to the punters. Is this the Norf London Uni? Shall I come and loiter outside with gin and doughnuts and big hugs?
nil desperandum. Xx