Sole survivor is stacked with healing debuff and only used on burst/hard-swaps (when you see your team actively switch to the target) as it should for proper efficiency, not on CD. It nerfs the most potent and main source of healing on said target, and where is that main source of healing coming from, the power house, the healer. Thus, said target getting killed is receiving generally 20% less healing output.
The onslaught cc is hardly reliable, you should know by now how this games latency screws knockbacks. The heal buff on storm's path is to have been expected, the fact that it isn't is dumb.
It's amazing how one dimensional roles are expected to be.
You need to learn how to drop stuff, you seem like the kind to hold on to grudges forever, it's not healthy man.