Classic duplicate battle.

West has to choose whether to open or pass. 

11HCPs and a good shape with 5/4 a good rebid either 2♠ or 2♦ if possible) suggests opening 1♠ and that is supported by the Kaplan hand evaluator = 11.7.

North should try a preemptive 3♦ even though vulnerable, it has good shape, 8HCPs and good intermediates. In fact Kaplan Hand evaluator = 10.0

Over 3♦ 

East will want to show support and with 5 card support and a useful singleton 3♠ is a good bid. Though a preemptive 4♠ could be right and that makes it difficult for South.

Over 3♠ or 4♠  by East South has a good hand opposite a Vulnerable weak overcall and should probably go 5♦ 

West may consider passing as he has 4♦ s and the bidding suggests 5♦ should go off. 5♠ which goes off 2 (should be doubled by south) = 500 which is better than the 600 for 5♦ making.