All depends on when you put you want the tax disc to start from apparently, if you put the 1st June you should get it 10-14working days days from then, if you put the 1st July they wont look at it until then so its then another 10 -14 working days.
I did mine a month ago took about a week which surprised me as it took 2-3 weeks for them to send me the V55/5 form but as Graham says i backdated mine to the beginning of the month but then why wouldn't you because it's freeeeeeeeeeeeeeeeeeeeeeee!
Yes you need to put insurance in as you need proof its insured to be able to be issued a tax disc, they will return it unprocessed if you havent included it.
It clearly states on the V55 what you HAVE to include
Well I posted it today!!!
I rang DVLA first to go through which bits I've filled in , what I'd put in the envelope etc, the man said it sounds like I've got it all in hand!!