How sweet is the Amaretto Sour cocktail? Does that make it "just for dessert"?

While the base amaretto is sweet and nutty, the addition of lemon juice gives the cocktail enough balance. It can absolutely stand on its own rather than being pigeon-holed as dessert only.

What's the best amaretto brand for the Amaretto Sour cocktail?

Disaronno is the most famous and works perfectly well, though some bartenders prefer Lazzaroni for its more authentic almond flavor and less syrupy texture. Luxardo also makes an excellent amaretto that brings more complexity. Your cocktail will only be as good as your ingredients, which is annoyingly true for both drinks and life in general.

Can I batch Amaretto Sour cocktails for a party?

Sure. Mix your amaretto, bourbon, and lemon juice in advance (but add 25% more lemon than usual because the flavor mellows when sitting). Keep it refrigerated and shake individual portions with ice when guests arrive. Skip the egg white in the batch because nobody wants to explain food safety protocols at a party. Add it fresh to individual drinks if you're feeling ambitious, or skip it entirely if you value your sanity.

Is the Amaretto Sour cocktail just amaretto liqueur and lemon juice?

In its most basic form yes, but using fresh lemon juice and adding elements like egg white or bitters elevates it considerably.

Is the Amaretto Sour cocktail strong?

It's moderate, because the base is a liqueur lower in proof than many spirits and it's built with sweet and sour elements, it can go down smooth. However drink responsibly and pace yourself.