So energy drain is a fairly high dps loss even with RS up. Theres no point in doing that.

You can pretty easily fit in 2 Festers inside an RS if you use swiftcast or miasma II or ruin II's.

There is no reason to delay contagion, as soon as all 5 dots are up you should hit it.

After RS is over you are free to rouse > spur then enkindle.

Or you can be lazy like me and rouse spur before RS on the pull, then enkindle about 10 seconds later when you have a free oGCD.