If you non KoS to craftkeepers and East freeport, there is a easy way to raise this faction.
Give Palatos Kynarn 4 Capt. Orlins Spiced ale (5 or 6 silver from the merchent right next to him).
Gives these faction changes:
+ Craftkeepers
+ High Council of Erudin
- Heretics got worse.
+ High Guard of Erudin got better.
You are given a beacon Mount as well, which is for the painting quest (basically, just destroy it at the end)