Don't be worried. You can get very good coverage, at a good price. But it does help to think it through a little ahead of time.
You are off to a good start. You realize that you are worried about flight delays. What else? Weather delays? What about illness? What about job loss or can't get away from work? You mention travelling with your parents (I traveled with my mother also, and she needed her own policy, no matter who pays for it), what if one of them got sick? Could you cancel both policies? Also medical coverage, you are going to Alaska, so that won't be as much of a concern, but you will be in Canada part of the time, and depending on how good your health insurance is, that could also be useful.
The good news is that ALL of these coverages are available, you just have to make sure the policy you get covers what you want, and that you know what it does and doesn't cover. To that end, I agree with Shmoo, talk to an agent on the phone. We did this, and they were very helpful getting us the coverage we wanted, and telling us the price difference for every option we could think of.
In our case, we had my family, my sister's family, and my mother, so we wanted to make sure we could retain the choice to go or stay if one or more of our group couldn't go for some reason. In particular, my BIL's job was high pressure, and there was a chance right up to the last day that he wouldn't be able to go, so we wanted to be sure we were protected. For this reason, we added coverage for our excursions, since we might have had to cancel within the 3-day window before the trip when Disney excursions become non-refundable. It wasn't much extra money and it reduced the stress on my BIL because he didn't feel like we had tons of money at risk those final three days.
