My archer is the exact same build. 18-27. I am only level 32, but I will have your exact build at 34.
At 35 I am just converting the attribute to 2 skills, max ath and put the 2 in IF. I mean, you COULD put 2 in PS if you want to melee, but you said you are pure, so put them in IF.
Don't bother getting melee wpf if you can still get a couple more archery wpf