Life draining rape dance I'm okay with, the nightmare inducing scream that scars all children forever will indeed be a bit hard to balance. As since there wouldn't be really anyway to direct it, it would potentially harm all players as well as enemies.

The life drain I think is self explanatory. You can absorb health from humans and hylians (cause you don't rape gorons, they rape you). It would also make sense like you said that you can't be healed by normal means, but perhaps shadow mages could produce their own kind of healing spell for you? Because while it would be fun to see you impregnate everyone, I don't think we'll always be in a position for you to drain someone's life.

The scream I am very welling to give to you since it does go within the Redead's abilities, but I feel until we can come up with a reasonable balance, this ability should remain in the void. Since Mog is my master of magic and is very good with coming up with balances, he may have some ideas to balance it out.