Re: insurance before title change?
They don't want to be responsible for something you don't own, since if it blows up before you buy it you haven't suffered a loss.
On the other hand, I've never had a problem post-dating insurance for a vehicle. I tell the agent I'm getting VIN# xxx on Monday, make the down payment, and he makes the insurance period start on Monday. If it doesn't work out, I can bring the cards back and cancel.
Someone said "Making good decisions comes from experience, experience comes from bad decisions." I say there are three kinds of people: those who learn from their mistakes, those who learn from the mistakes of others, and those who never learn.