3 dúvidas sobre o Simple Present Tense

Caros amigos, tenho três dúvidas a respeito do simple presente tense.
Ouvindo essas músicas ontem, me deparei com as seguintes frases:

1ª - Elton John: THIS TRAIN DON'T STOP THERE ANYMORE
I used to be the main express
All steam and whistles heading west
Picking up my pain from door to door
Riding on the storyline
Furnace burning overtime
But this train don't stop,
This train don't stop,
This train don't stop there anymore

* POR QUE É USADO "DON'T", O CORRETO NÃO SERIA DOESN'T?


2ª - Bob Dylan: JOKERMAN

Jokerman dance to the nightingale tune
Bird fly high by the light of the moon
Oh, oh, oh, Jokerman

* POR QUE "BIRD FLY" E NÃO "BIRD FLIES" ????


3ª - Abba - THE WINNER TAKES IT ALL

The gods may throw a dice
Their minds as cold as ice
And someone way down here
Loses someone dear
The winner takes it all
The loser has to fall
It's simple and it's plain
Why should I complain.

* DIE - DADO (SINGULAR)
DICE - DADOS (PLURAL)

POR QUE "A DICE" ??? - NÃO ENTENDO ESSE ARTIGO INDEFINIDO NA FRENTE!!!!


Atenciosamente,

Lisa