I've fished down there quite a bit, but I've never been to Playa Tambor. It looks like you'll be on the inside of the Nicoya peninsula, so the surf should be minimal.
I don't really fish the Pacific coast much anymore because unless you're looking for bluewater, there really isn't much going on. If you get lucky and the sardinas are in, you can expect some great topwater action with the jacks, but most of the snook have long since been eaten, and the roosterfishing has never panned out for me.
Things may be different in Playa Tambor, so I don't want to rain on your parade too much, but for a fishing vacation you're a lot better off on the other coast.
That area's generally very safe, but petty theft is an issue everywhere down there, so keep your eyes peeled and don't leave anything in your car.