@MagnificentWang
Royal Guard is definitely worth some investment. She will protect your injured toons (besides AoE) and has a reliable stun. She will also be very useful in GW, maybe more than STHan. Moreover, stars are not very important for her, just get some protection mods because protection is unaffected by stars (and she will not do any damage even on 7*).
Old Daka is the only healer for dark side (Talia is garbage), but she will be useless on your level quite fast if you don't get her to gear 8 or beyond. With RG and soon Sun Fac your toons should be save.