Purchasing saver fare as a AA Gold/OW Ruby allows for 2 free checked bags for the status member only.
Relevant fees waivers/exceptions for baggage can be found at this link: https://www.alaskaair.com/content/tr...ers-exceptions

You should be able to select preferred seating and will be listed for upgrades, but temper your expectations as the odds of that happening for AA Gold is near the bottom of the list.

AA has a pretty informative page on the benefits when travelling on AS:
https://www.aa.com/i18n/travel-info/...a-airlines.jsp