What subject was your D? Only issue would be if this was in one of the required subjects. As long as you meet the minimum requirement it doesn't matter. And your GCSE's sound just fine. Don't worry!
BCCD is not flunked or really bad! Not at all! Especially if it's BM6 you are hoping to apply for. Most people on the course have the minimum required although some have extremely high. It doesn't matter
They do indeed look for people who have not really had the best chance to do the best they can and have the potential to be great doctors so you're right on track, as long as you're getting work experience if you can. Your grades have not affected your chances at all. Also, remember uni's will only loook at your final grade, not your modules!
These rumours are rubbish. Some people get on it and are lazy, and then they fail and get kicked out. It's not easy, it's a fair amount of work (nothing like when you start the 5 year once you pass, but still). Just ignore these people.
www.bethaney.co.uk/blog - should have both my personal statements on there. I think the one you want (newer) is on page 2 (click older posts at the bottom).
It's a 3 day week and it goes a lil something like this:
Tuesday - Human structure and function (HSF) lectures all morning (this is biology stuff) ( 9 - 1 )
Professional practice (PP) all afternoon (this is sociology, psychology, how to be a good doctor etc). ( 2 - 4)
Wednes - Morning only - alternates between PP lectures and placement.
Thursday - same as monday except PP is statistics.
There is no difference in doing a foundation course like BM6 as it is just a year at the start and then you join the BM5 intake (so I did BM6 2010/11 and will now join BM5 2011-2016). Unless you mention it when applying for a job they won't know, and even if they do they shouldn't care. There are much bigger things to judge you on by then haha!!!
Hope this helps!
Good luck!
P.s there are some UKCAT tips on the blog somewhere too in case you were looking for any!