The electricity available at Oregon state parks varies, but the pedestals at Fort Stevens are modern and include both 30 and 50 amp. Check with the Oregon State Parks site on their reservation booking platform, Reserve America, to see what power is available at the site you select. 50 amp is not universally available at all Oregon State parks. For example, we stayed at Viento State Park a few weeks back, and they had power at each site, but it was 30 amp only (with the obligatory 20 amp household outlet).

I believe so, pretty sure we had 50 at ours.

Yes

Yes it is, all Oregon state parks I am aware of have 30 and 50. You should consider keeping a 50 to 30 dogbone adapter and a 30 to 15 adapter just in case

Yes -- 30 and most sites have 50 as well.

Yes, the pedistals have both 50

Yes

Yes.