Thank you for sharing your photos and narrative! You were quite fortunate to see killer whales; they are not seen on every trip. Humpbacks are the most frequently seen larger whales in that area of Alaska. We did see fin or finback whales on one trip but they are a rarity.
We take cruises with Major Marine several times each year when we visit Alaska. I have never been able to figure out their assigned seating system. We have been on boats that were empty and everyone was crowded together. We always bring our own food and often we are seated almost next to the buffet table. It really does not matter to me since I use my chair to store my items and spend the entire trip outside, even if it is raining.
The Spruce Moose is a great place to stay near Moose Pass if you have a large group. They have chalets that sleep up to eight adults.
We rented a condo at Girdwood several summers ago and were surprised at how affordable it was. Rather than stay in Whittier or drive from Anchorage, Girdwood provides some good options. Many of the condos are used by skiers during the winter, so they tend to be slightly cheaper in the summer.