Inflationary vs deflationary instruments. Sovereign currencies are typically inflationary because central banks print them to a greater or lesser degree, National Assets like gold or land reserves are typically deflationary. Bitcoin is more the latter.
No, I think you're right in a technical sense. My point was that, maybe because the relevant timelines are longer for nation-states than households, their easily liquifiable assets tend to rise in value over time. A country might have gold reserves, which reduces the risk of lending to it and lets them borrow at a better interest rate. The gold reserve isn't money, the government sells bonds for money, but it can be converted to money fairly quickly.
Bitcoin, similarly, is more of an asset with a fixed supply that can be quickly converted to money. Calling it 'deflationary' is probably some imprecise labeling on my part.
If it has a steady supply and things are getting easier to produce, yes. Typically a larger amount is minted each year so that its value relative to goods and services decreases in a predictable fashion.
No, they're competitors for the stores of sovereign wealth that are the backing of sovereign currencies.