There’s not much of a “synth world”. We have the one store, and it’s pretty small. Lots people into the hobby, but aside from events, there isn’t a tremendous lot of public manifestations (so you’ll def want to hit that event if you can).
If you want a low key lunch on cap hill, Tacos Chukis is great. If dinner with a movie sounds nice, Central Cinema is fun and feels very “local” – but a it’s a bit of a walk on cap hill. You have Too Many coffee options. Depends how you’re getting around? If you’re driving/ridesharing, Seattle is small. Everything is close, barring traffic. If you’re mostly on foot, most things are concentrated to areas; so if you’re staying in the city proper, you’ll have access to most everything within a very small area. Use the light rail to hop between downtown and cap hill.
Seattle is an easy place to visit. Whatever your fancy, you’ll have some good options.