I figured out the first tip the day that the Halloween quest went live on Origin. I shared with some of the Elite's here and they said to keep it under wraps. Today TopTwo and I agreed that it is too close to the end to sit on it any longer.
Since you are invulnerable when you are transformed for the Halloween quest except to the creatures that saw you transform you can do several interesting things while you are transformed.
Here is what I was able to put together so far.
1. You can tame whatever you want and it will not eat you. You will get the message that you have angered the beast but it won't attack you.
2. Walk through the quicksand area at Twisted Weald without getting attacked by the changelings on your way to gather Dreadhorn keys
3. Mark runes in dangerous areas without getting eaten.
4. You can heal the transformed Gypsies while transformed yourself. Be careful for creatures that damage with an aura, such as many mobs in Ice dungeon and their area cold damage.
5. Use the transformation to become invulnerable for accessing Sanctuary, or to get into the exodus dungeon for the Spellweaving quest.
There is a thread in the Elite section about this that I don't have access to so if there is something I've missed that you feel like sharing feel free to add it here.
