[bpejjssoe]

Seems quite nice. The only thing that I might say is that you could shift some of your 'what I have to give' stuff into the first paragraph. At the moment, the first paragraph reads a bit like a 'what's in it for me' spiel. I know that that's pretty much what they ask, but having filled in numerous applications of this sort, it's generally better to go with a little more balance (within the bounds of the question), especially in that all-important first paragraph.
There are a couple of grammatical points that could do with fixing up, and seeing as it's an application for the post of English teacher, you can't really let them slide. I don't have time right now, but it'll give me something to look forward to after practice this evening (rubs his decrepit pedant's hands together with glee).