Good catch. Thank you. I re-worded the sentence to make it more clear. Much appreciated!

Yes. While it’s true that a weaker base forms a stronger base, it’s still an equilibrium, where the concentration of deprotonated ester is about 1 x 10-9 relative to the concentration of alkoxide. However, that deprotonated ester is then immediately consumed in a reaction (the Claisen condensation, which results in formation of an alkoxide base). As deprotonated ester is consumed, the equilibrium then re-establishes itself (Le Chatelier’s principle). In this way eventually all the ester is converted into the final reaction product.

It goes to show how fast chemical reactions can be when an equilibrium difference of 1 x 10-9 can still result in a reaction going to completion.

Where’s the typo? That’s what the reaction is called, but neither the name or mechanism is important for comparing the relative strengths of the bases.

Fixed. Grateful to you for spotting the typo!

I don’t have a good value for that. If you find one let me know.