Have been playing this a lot lately, and just wanted to share my thoughts.
Chandra is definitely fine as a 2-of. The card I feel like I want more of often is Veil of Summer, but I'd also like to find room for an Ancient Grudge in the main. I put one in the SB too. I might shift things around and move a Flusterstorm from the main (I subbed 2x Fluster, 1x Spell Pierce for the Missteps) and put a Grudge main and that might be great.
Still, I love this deck quite a bit. I have had some really insane games with it, and it snowballs really quickly.