Can't answer most of your questions, but might be able to provide a little view based on my experience.

The wife and I did an Alaska cruise for our 30th Anniversary just before Covid hit. We were on Holland, though doubt it would be the best choice with kids. Of note though is we stayed in an aft facing Neptune suite. It was wonderful as it had a wrap-around balcony. And being at the back, we usually didn't have the wind cutting through us. We even had breakfast served to us out on the balcony one morning. That balcony was great for seeing everything from there. Our cruise was late May, early June, but the weather turned out pretty good for us. So no complaints there.

We broke our trip into to parts. First, 7 days of cruising from Vancouver to Seward. I liked the 1 way cruise as it seemed like we could see more of the Alaska coast. Plus it allowed us to then take a bus to Anchorage and rent an RV and spent a week driving around Alaska. The benefit of the RV was we weren't as dependent on the weather. My wife originally wanted to drive to Valdez and sightsee there, but it turned out the weather was going to be 40s F for highs and rainy. So instead we drove up to Denali where it was sunny and 70F and did some sightseeing there. Then we drove down to the Kenai peninsula, did some fishing and hiked out to see the salmon jumping. First time we have ever rented an RV. It was a lot easier than I was expecting (and worried about). We had no issues finding RV parks for hookups.