i think neither blood caked or necrosis is very good for tps, you will probably be using rune strike a lot, and rune strikes replace your autoattacks. how can you not have summon gargoyle? you should really take it, imo. threat gen is a complete non-issue for me, so it doesn't matter if the threat doesn't go to me (not sure...does garg get threat?). and the damage it does is awesome. DPS is still important, the faster a boss dies, the less mana a healer needs to keep you up the whole fight. 5/5 desecration may not be necessary, but you should really REALLY get wandering plague 3/3. it is amazingly good. this is the build i use and it works great.
http://www.worldofwarcraft.com/info/...03150203133151