Cast time has a more complicated formula now.
You get 100% reduction to variable cast time if (INT + DEX*2) >= 530; formula is no longer linear.
Also, most skills now have fixed casting time, which is much harder to reduce - only things that explicitly state that they reduce fixed cast time will do so, and multiple % mods don't stack. The important fixed cast reducers are Sacrament and Temporal Dex Boots.
For all the details, see http://irowiki.org/wiki/Cast_Time
When renewal first hit, throw kunai was applying the element modifier TWICE. This wound up making it possible to level a ninja from 35 to 99 in under 2 hours, 1-shotting everything from when you got throw kunai maxed to 99. It was kinda OP. This was fixed when the ninja second job (Kag/Obo) was introduced.
Edited by DrAzzy, 12 September 2014 - 10:17 AM.