Not knocking your build... but greater spell focus is really not necessary - you could easily ditch that for either Spell pen (and take the clonk path!) or empowered healing. Entirely seperate topic, but i personally feel maximize AND empower on a BB is overkill. To me the strength of the class is versatility, so why build for only one thing? To each their own, not knocking your build, but i don't think that little bit more out of your BB makes up for giving up regenning turns and the RS heals.
In the end the burst alone is equivalent to so much free SP its just ridiculous - I crit on my burst for upwards of 300 hp, and I'm only level 13 (10 levels of cleric). And it regens... and all i did to invest in it really is pick up the PRE.
Just my 2cp.