I'd not use such big blood textures for that purpose as they make the game slower. Big texture = maybe big memory usage.
Just learn to watch the health abrs of group members even if you are tunnel focussed on teh enemies
Always keep one "oh ****" heal on your dd bar. Should work in most content.
If an addon needs to tell you to stop focussing on dmg you should either play a DD instead
or learn to have the group members in sight. Maybe use other positioning and always stand so that you got them in view and can use the health bars of the players above their heads (if enabled).
This will also teach you how to position good for bonus group dmg skills like the healing staff's 3rd skill's morph or conal front heals, as a benefit you can watch the enemies and see when they cast and maybe eben interrupt them with the destruction staff's 1st skill morph.