I did mine in new Yr, think it only took 10 days! 2 months later all over the news how f%#@×*^ up they were gonna be later. Looks like they've sorted it now....
I've been asked 4 times for exit flights at Heathrow. I had the exit flight on all occasions. I don't think a bus ticket would have cut it really but I don't KNOW that for sure ....
as far as I've seen you'll need a residence cert and a rental contract and TM30, but it does seem to ne getting diffucult, unless u hv the non o already.....