There isn't any, unless you count Robin van Persie who moved to Arsenal that year...
No to my knowledge.
No,no one has played for Liverpool, Man U, Arsenal andChelsea.
Mkael Silvestre fo Man United and Arsenal
Arsenal have failed to win the Champion league uptil today, they reached the final once in 2006 , but lost it to Barcelona 2-1 was the score.
Yes Arsenal beat AC Milan 2 - 0 at Milan
Michael Owen has played for both liverpool and currently Manchester united
The other obvious one is Jens Lehmann who won the Premiership with Arsenal.