It's possible to see the Aurora, barring (1) clouds, or (2) no Aurora activity. October can be cloudy and nasty on the Arctic coast - temperatures around freezing or below. It's much dryer and frankly more conducive to seeing the Aurora later in the year (albeit colder too.) But Barrow is indeed interesting from a cultural viewpoint. I would not expect there to be bears about, BTW.

Adak is somewhat historically interesting - former major US Navy base trying to figure out a role for itself now that the cold war has moved elsewhere. Terrible weather most of the year, but the Chain is a fascinating and beautiful area. You might want to look at the trip report on an FTer's recent tour of Juneau and flight out to DUT. You might find Unalaska more interesting in October than Adak, as things really start heating up for the crabbers in October. Pretty much zero chance of seeing the Aurora on the Chain, though.