On the flip side, most things that bring people into the city have been cancelled indefinitely (sports, conventions, school, etc).

Maybe Seattle will appreciate more, maybe it'll slow down or even go backwards for awhile, but if you're not cash flowing in the meantime it sounds like that's a gamble that's more trouble than it's likely worth.

But it works, simplified, like if you owed $500 to CA but paid state XX $300, then you only have to pay CA the $200 difference.CA may not be able to get blood from a turnip, but they will suck that turnip dry before they let it go.Likewise if you, say, play professional sports for a team in state XX, live in state XX, make $20,000,000 a year, play 1 out of 20 games in CA, they want that 1/20th of that two million taxed in CA...but they will give a credit for the taxes you paid in state XX according to the interstate agreement. 

Drugs, alcohol, gambling, abuse.  

Retirement accounts are unhedged gambles on future tax rates, and the odds looks poor.

the trick is to have a house near a popular bar or sports arena / field if you want to cater to a younger crowd

It's more gambling than anything else.

Gamble you'll need to consider.

For sporting events, concerts & festivals to be allowed? 

Because of the low humidity, evaporative cooling keeps the house comfortable even on the hottest days and is way less expensive that A/C. 2) Outdoor sports.