pugwash - I didn't write anything like 500 words for each - more like 150-200 I think.
The responsibilities thing is certainly a bit daft, but I suppose it's looking for non-work related things (i.e. things you weren't paid for!) I stretched it a little and put in a Uni Society post I held (well, Uni is sometimes called college!).
Can't say that I found the form particularly problematical, it's fairly standard for any type of job application I thought! Maybe at 28 I've had fewer jobs than most - I put down 5 jobs, 2 were part time while at Uni and one was a summer internship. The other 2 are the ones I've been in for the last 8 years. I missed off my part time job when I was at school as it seems a little far back now and was only 1 half day and one evening a week.