Hey Reddice
This books looks solid for a timing attack. This book looks like it would play out very similar to how the German Championship match that was posted a few weeks ago.
Sunfire Amulet- I know you mentioned you were considering this. Because of the extra life and plethora of healing spells, I wouldn't be afraid of sacrificing some armor to buff your creatures or get out attack spells against crucial targets. Since you run a lot of heavy hitters you're setup to go for a safe transition should your opponent freak out and rush for you. You usually see Deathlock or an attempt to dissolve through kidnap/shenanigans. If you get the KOW up round 2 (what your plan is), you should be good to engage if they choose to.
I would consider dropping a seeking dispel for an ignite. It gives you slightly more options, but is also good for fishing for nullifies.
I would trade a dispel for a disperse. In my experience I find range 2 is easy to reach, and it savs some mana. I would also consider a Crumble, but that is up to you.
3 Chitin armor is very expensive. I'm not sure you need all that with the large amount of healing you have.
Purify while it seems useless is actually really good for the Priestess. The ability to get rid of Poisoned Blood and Ghoul Rot in one quick cast is very useful. Those are two very common curses to have in dark books. You have a mage wand. You can also cast purify on yourself if you have nothing better to do for 0 mana. Nothing happens but you gain a total life. It's free life!
Otherwise run the book in a bunch of games. It takes time to figure out the correct round to engage with this kind of book. Mainly because you have to react to how the opponent is building their power in comparison to yours.