1. It only becomes useless when you reach lvl 70, so you can skill it if you want to grind all the way through. 2. I'm not an expert with grinding those low levels, but if you find me on Donn9e in-game when I'm awake and not afk I'll give you free orbis etcs to reach level 30.
One more question. I'm level 33. Is it too late to start putting AP into INT for washing, should I start over?