Most of your packing questions can be answered by the time of year you're going, length of the cruise, and ports of call. Let me explain:
You could be going on a 7 day cruise to the carribbean, but if you're going in winter, you'll need coats and long pants for the first few and last few days. The further north you are, the colder it will be.
However, if you're going on a 7 day cruise in the Fall or Spring, the most you may need would be light jackets.
Also, if you're going in the summer, you wouldn't need jackets at all!
Likewise, the longer the cruise, the more you'll need to pack. You'll need more clothes for a 7 day cruise than a 3 day one.
All that said, if you're going to colder climates, you'll need more long pants and jackets.
I see you're going on an Alaskan cruise, so you'll probably need clothing for colder temps