Yes, but it has nothing to do with being able to explain the strategy behind perfect play.

super weak: we know there is a perfect play
medium: We know perfect play
Super strong: an algorithm can from any position, with mistakes already made play the rest of the game perfectly.

nothing about strategy

Yes, I take it that any algorithm is what people mean by "strategy" in game theory (rather than something more literary like "I'm going to follow an influence oriented strategy"). Peering down the game tree, on the other hand, doesn't count as a strategy.

Is that true? I would think that a completely solved game tree of every possible position would qualify as super strong.

I can't actually remember Otake Hideo's opening principles any more, and many other useful things. Fuseki for me is now about:

1. Specific knowledge, I know in this sort of fuseki these are sorts of joseki options.

2. Joey's spin on the direction rule: approach corners, try to get the 3-3 point, try to get the wider side.

Seems like a reasonable assumption that at different phases of one's development one can, and in fact needs, to refocus. Strategies lose their value when one's opponents know what you're up to and even worse, know the countermeasures.

My experience of go isn't so much that one is trying to blindside your opponent so much as just trying to keep playing normal moves (including the normal responses to your opponents' strange plan).