You won't do great damage with that, no*. For one thing you seem to be planning to cast shadow bolts a lot but you have not taken the Ruin talent which is pretty great for increasing the damage of that spell. For another, dots like CoA and Corr don't do great damage in heroics as trash tends to go down so fast that they don't run their full course. If you want to use the felguard I'd suggest something more like:
http://www.wowhead.com/?talent#IZ0GchkAkibcGzZVbhqrzuVqT
FG does decent damage and you can either spam incinerate or rain of fire depending on the size of the groups.
* feel free to come back and prove me wrong btw.