Except for the ginger buy it in ANC so you don't have to pack it and worry about customs. You can also get what you have forgotten. Lots of stores. If that short of time you may have to rethink your visit.
We had good luck with Costal Helo in Juneau. Call direct. Remember AK time is one hour later than Seattle. Many times weather cancels so be ready with back up plans. Likely been full for several weeks but may have someone canceled. Skagway may have better chance with better weather.
I think that most of the rental cars have to be picked up at the airport this year. Not 100% sure but something to check and factor in getting to and from.
Spend the first sea day going around to spot out the best spots. Consider all types of weather, entering and exiting the glaciers, and look for spots that others might not find. One HAL ship had a great deck that the access was through the gym.
Find some photos of the glacier from 2023. I think that it has receded in a major way since 2016. It won't be long in glacier years until you will not be able to see it from the visitor center much like Portage Glacier.
For Sept cruise look into Ketchikan Herring Cove tour so you can see black bears eating salmon. The Skagway train will be about the same price either cruise line or on your own but cruise line to train will be closer walk. Juneau whale watch. Victoria with late arrival just walk to downtown in the dark or don't bother. Sept helo likely not flying in Sept a few other tours will end in Aug. Tracy arm long boat ride 90 min each way to get there.