If you want to be effective with throwing you have to make your build about throwing .
It's just way more easier to drop 50-75 wpf in xbow. You will have three time more ammo, do the same or more damage, have five time more accuracy, twice as fast projectile speed, no need to invest skill point, shoot people at medium-long range, no wpf requirement, you can use every armor you like, you can use xbow and be effective at very low lvl etc...
Only drawback you need some cover to reload.
It's really a no brainer