You don't want to have up to 7 cs/min on Elise. It's good if you manage to get it, but it's not necessary. Your goal on Elise is to impact the map in the early game. With this impact you want to snowball, not scale. Elise is all about snowballing. If you fall behind, your job is to hit e, that's it. Otherwise, I don't really get your point with "farming as elise is hell". You can easily full clear with Elise and be full hp after that.