I agree with Trackypup! While I personally like to use websites like kayak.com for researching flights and prices, I always book directly with the airline. They will notify you immediately if your itinerary changes and try their best to assist you should that cause you any problems.
As for travel insurance, I definitely agree with that one! I could list a hundred reasons to purchase travel insurance, but only one reason people may not purchase it and that's the price. If they can afford to loose the money they spent on their vacation should problems arise, then they don't need the insurance. But since most people can't afford to loose that much money, it makes sense to get it. As you said, it's always best to purchase an independent policy as you'll usually pay the same or less, but get alot more coverage for your money.
Also, keep in mind that there is a big difference between travel insurance and travel protection and it's important to make sure you know what you're getting. I started a post about this here; Travel Insurance vs Travel Protection