South and West will pass.

North will open a weak 2♠ (normally 5-9 HCPs and 6♠). In position 3 some people will have a wider range as partner is limited  to <11 HCPs and you are unlikely to miss game and the opposition may have game values. So 3-12 HCPs and even 3 HCPs may allow a disruptive pre-emptive weak 2 bid.

Here is Larry Cohen discussing weak 2 bids https://www.larryco.com/bridge-articles/weak-2-bids including bidding them with 5 cards.

With 19HCPs and no ♠ stop, he can support the other suits, though better to have 4♥ s, he will double.

South will pass.

West has a totally balanced hand and is forced to bid.The best reaponse is 1NT showing a stop and 7-10HCPs. Here is a good link on doubles https://www.bridgebum.com/takeout_double.php 

North will pass.

East with a good hand will raise to 3NT.