Nice they count beer in glasses, not bottles or barrels :D
Traditionally it was really tiny cups like teacups with the teapot.
Why 了 can't go after 酒?
Most often goes after the verb.
It usually goes immediately after the verb
It can as the second 了, it'd sound unnatural as the only one and after 酒
The audio for "le" is incorrect in so many lessons--or am I missing something? I hear "liao" from the audio instead of "le".
了 has two pronunciations (with different meanings.) In this sentence it's le but in some other contexts it is liao.
The audio for 了 is wrong here. You're right. 了 is pronounced a "liăo" with another meaning, but in this sentence it should be "le".
It is funny we learn the word for beer in the same lesson as we learn the word for German.
Is the 'le' really needed after 'he'? What happens if we left it out?
The 了makes it past tense. Without it it's ambiguous; you might be asking how many she intends to drink.
How come we cannot use 几个 in place of 几杯？It seems confusing that sometimes we can, and sometimes we cannot...
You're probably right.
个 has very vague meaning, like "thing." In this context, I think it should be clear that a "thing of beer" is a glass, not a barrel or a vat or a frozen chunk or something.