For me personally:
Jiyeon - I think she is a very safe member. She may have a lot of activities, but she is undoubtedly the face of T-ara.
Hyomin - I think she is also safe. She's always been loved in T-ara and don't see her leaving
Soyeon - Also, I think she is safe. Soyeon is the voice of the group!
Eunjung - I, am unsure. She's had an injury of late and CCM seems to be pushing her back in performances.. CCM will only be going for the healthy members, and CCM is evil enough to boot her for it.
Qri - My bias, not too safe. She's one of the least appreciated members of the group, and she's also the second oldest. However, CCM seems to be really pushing her in the last few promotions, plus she is really improving. Also one of their best Japanese speakers!
Boram - I feel she is the least safe. She's already voiced her opinions on her health and everything, I feel like CCM could be using this to get rid of her.
Hwayoung - I'm really not sure. While she's the newest member, she does seem to be a great rapper, and has great abilities. However, CCM has never really used her. She's got next to no lines in most songs, and CCM always seems to favour Hyomin and Eunjung for rapping.