Some NW mechanics questions

if uw ant. drop avenger. put it only to like 21 when it hits 6 monsters. the rest leaves u with around 9 SP for whatever skill you need. and once you hit 120 ( or leech there anyway) it doesnt matter cause avenger is pretty pathetic for bossing and your done training anyway.

I was thinking of dropping several skills.

Perhaps:
- lv 19 mastery
- lv28 poison bomb
- no 1 point in shadow web

This will result 5 points in Vanish. 5 more from Vanish or Avenger.
Wait-- does Venom work with Vampire?
If yes, drop Avenger for sure?
If no, drop Vampire to lv16 and Avenger to lv29 or steal a point from Alchemist or booster?