I'm going to take these one at a time. I'm a primary teacher but thinking of this from a secondary point of view
- listen to music players whilst completing work (unless it's a music lesson/relevant) I see no problem with this while children are working independently, in fact I often use music in my classroom but not ipods etc as the kids I teach are too young to bring them in. At an older age I think it probably has benefits as long as it's not while the actual teaching is happening
- eat and/or drink (not water obviously) Again, I don't really see the issue. Esp in secondary when lessons can be longer, i like to nibble while I'm working (at home, obv not while teaching), so see no reason why kids can't
- get up and walk around at will I massively admire anyone who can stop this at secondary level. IMO it depends on the reason for the walking and this can often be controlled. Eg. its perfectly acceptable for children to get up to get a book they need, but not to go and have a chat
- swear/use foul language to you/each other under their breath (whilst you pretend not to hear) I think this depends on how often it occurs. Its going to happen between teenagers and may not be worth making a fuss over and interrupting the whole class for. If its ongoing or seems like bullying then that is different
- dry-hump each other (to which you merely raise an eyebrow) Never acceptable, I would take further
- routinely turn up to lessons with no pens, pencils, books I'm sorry, why is this the teachers fault? I have no control over the children outside of my classroom. Being prepared is their/their parents problem, not mine
- treat the floor as a bin not on your nelly
- deface books hells no
- break pens etc They are free to break their own pens. again, not my problem. School supplies or someone else's pen, no, action would be taken
- use their mobiles for texting (against whilst you pretend not to notice) No, I would not allow this, although it could be hard to stop if their music players are their phones, see point 1