What happens when bone shield or vampiric blood are up? Are you saying those don't work? Rune tap is a 30 sec cd. Are you using it frequently? Do you have a good way to watch Blood Shield? If not, get power auras. If blood shield is not up, death strike should be a high priority. Try not to overlap CDs so you don't waste uptime on any of them.
Having said all that, is your group making total use of cc? Blizzard is expecting you to when they say your gear is ready. This ain't WotLK. The average pack is too much for anything but and overgeared tank/healer combo. CC is expected.