Bless needs to be a 2 AP, 0 SP skill. The entire problem with it is that it costs a Source Point.
Enemies get a ton of different ways to curse surfaces for free, even without the Source Point cost it would be difficult to keep up. I just simply stopped trying and lived with all the surfaces being cursed, because it's just a poor use of Source trying to keep up.
There is simply no counterplay for Curse, and that is a shame.
Bless is absolutely no good costing any Source Points at all. Any other buffs will not fix the problem.