It may be the "last thing" in your eyes, Peter, but for most of us the real world intervenes in these decisions. The extreme opacity of the insurance business requires a team of Philadelphia lawyers to decode the tiny type word-salad terms of a policy. It is fascinating to me that the so-called underwriters will take all of the information you listed (and sometimes more), apply their scientific risk analysis, and come up with (in my case) quotes that vary by a factor of 5 (top to bottom) for the "same" coverage.
With your expertise, you can probably spot these disparities a mile away. For nubs like me, it may not be so obvious or even evident. Professionally, I sometimes become peripherally involved in insurance litigation - funny how the lawyers for a megacorp insured and the lawyers for the megacorp insuror can read the same words on the same piece of paper that they both agreed to the year before and come to 12 figure disagreements. Not sure the average boat owner has a real basis for comparison other than the basic (policy professed) coverage numbers and cost. Agree that there are quality factors in insurance, but it's a challenge to figure them out.
I don't think there's a person here who can't read the insurance policy in it's entirety. Most just don't. You find all the exclusions and limits. I do agree with Pau Hana completely. If you don't feel comfortable reviewing the details of a policy then get someone who is and who you can trust to assist you. To compare two policies based only on premium or a couple of top level factors can be extremely dangerous.
As to policies being difficult to decode, I've dealt with policies that were, but I would not put boat policies in that group. They spell out clearly what is and isn't covered and they define the terms they use. The problem is there is no standard as in auto policies, so they can vary a great deal. I will say too that the little extra missing in one policy can often be obtained for very little more.