Advice needed from Seattle members

The Seattle region sits on the east edge of Puget Sound for the most part and Seattle itself is wedged in between the Sound and Lake Washington, This means you really only have one major north-south arterial (I 5) in Seattle proper and only a couple major east-west ones feeding into Seattle across Lake Washington (I 90 for one). This makes commuting by car a slow and arduous process at best and nearly impossible at times due to weather and traffic bottling up I 5.

Because King Street station is literally across the parking lot from the stadiums, commuting in by train from somewhere far more affordable (and some would say far more livable) than close-in Seattle looks to be a real option for you. The more local Sounders are the commute train, but still run all the way in from Everett in the north and Tacoma in the south. While not in the same league as northeast corridor high speed rail timewise perhaps, the regional commute Cascade Talgo trains coming in from as far away as Eugene Or and Vancouver BC make commuting in from as far away as Olympia in the south and Mount Vernon in the north quite doable, although with less flexible and longer commute times.
Type Sounder Train or Amtrak Cascades into your search engine to look up their timetables and maps.

i've met a lot of people over the years living on the Olympic penninsula and various islands in the Sound taking ferries (Washington State Ferries) to work in downtown Seattle, too. If the scheduling worked out for you that might be a viable option also.