I think that the writers really took a clever take on the shows finale, with that rendition of Bohemian Rhapsody by the opposition.
I personally wasnt a fan of the ending. I loved the performances, but the actual story wrapping up whilst providing a great lead for season 2 seemed a bit rushed. Although that is probably explained by the fact the second half of the series was rushed.
The show is pretty weak overall dramatically. The farcical behavior is mixed in with some musical numbers that are genuinely moving. The drama is hit or miss, but mostly miss. It seems like the need to keep 14 characters coming and going means that the dramatic moments are little snippets that often seem after school special.
Cory Monteith is pretty old for a 16 year old (he's 28 in real life) and is almost the same age as the actor's who play the teachers. The rest of the high school kids are 20-28 years old actors.
Jane Lynch is the only true comedian, and I think she picked up a lot of her skills from working with the British director Christopher Guest. Farce is something that the British are the ultimate masters of.