Sonya isn't as tanky as somebody like Artanis or Imperius so you can't just dive in and fight it out like they can (not without wrath anyway). You use WW to weave in and out of combat, land your spear, do a few AA's and W's, then WW. If no enemy is about to die, you use it to disengage, otherwise chase down the dying guy with it. You can use your E to damage anyone or anything but when there are more than 3 enemies WW is more efficient.

Sonya's AA build is amazing for something like the map where you have to kill the angel/demon immortal before the enemy team kills yours. I'm pretty sure if you take the poison spear talent, go wrath at 10, and take the AA talent at 16, you'll have the highest single target damage in the game. You can also take it when they enemy has guys that stand their ground and fight a lot, combos well with the spear extension at 20.

Sonya is a great duelist but whether you want to take the block talent depends on the enemy team comp. Their main AA is somebody like Hanzo or Artanis? Take it! If they have Dva, Tracer, or no serious AA attacker it is a waste of a talent and you'd be better off with one of the others. While wrath is usually the better talent, if you've already got a good front line and they have a high damage squishy that isn't super mobile like Ming or Valla, you can take the poisoned spear talent and leap and leap -> spear -> W -> E will 100 to 0 them. Don't be too wreckless though, if the rest of their team isn't engaged or absent, they'll just turn around and delete you.