We probably need to see some more parses (there may be some out there & I may be lazy), but my guess is that Revenge still accounts for good damage. If you compare Cleave with Revenge I will assume you talk about AoE situations in which rage is not an issue. And then we must remember that Cleave and Revenge are not mutually exclusive, meaning - you can use both at the same time since Cleave is off GCD. If rage is not an issue, why use one skill if you can use two? Revenge will probably replace Devastate, and we know which one is better.
As for Blood Craze and Field Dressing on a patchwerk boss with a 2.5 attack speed (that's the default, right?):
Multipliers: 0.1 proc chance, 1/2.5=0.4, avoidance ~0.4 (rounded), Field Dressing 1.2, Blood Craze 7.5%.
0.1x0.4x0.4x1.2x7.5%=0.144% hp per second. Assuming there's no inner cooldown. That's crap on a 50k tank that's 72 hps. However, damage ticks come more often than once every 2.5 seconds, and we should remember it's 9% over 5 seconds which is more than 72 hps when it actually procs. We need to compare it with other forms of healing, maybe a healer will be able to shed more light on how we should look at Blood Craze.