What happen if you're all paid for and someone gets sick or there is another kind of family emergency. What if (god forbid) another 9/11 happens? Many years ago my folks had a trip planned to Russia. A week prior to their leaving the Chernobol nuclear accident happened. That was close to an area they were going to. Would you have wanted to go there? They cancelled and got back all they had paid. So, do you need insurance? I wouldn't make reservations for an expensive trip without it!
You need to verify all the particular coverages you may need. "Sickness" has a wide range of coverage and sometimes NONE. Same with who they determine who "family " is?? For clairfication- I was to travel 9-11-01 and sail 9-12 on the Spirit- no insurance and everything refunded and a free cruise.