I thought her words were wise. She is still under Channel 7, so she probably doesn't want to burn bridges with those elders. I don't think she wants to stay in her comfort zone, since she took a lot of fierce/strong n'ek roles like in Jao Nang, Lilawadee Plerng and most recently Buang Sabai (she was n'rai but you got what I mean). It's just that maybe she is preparing for her detour from channel 7 so that she doesnt come off as an ungrateful child.
Look at Noon Woranuch. Afaik she was leaving on good terms with Ch7, therefore she has no problems coming back to play in Plerng Sanaeha. Of course Tubtim doesnt have the same position that Noon had with Ch7 but she has been building her image as a clean n'ek, so it's understandable she wants to keep that till (at least) the day she leaves. In her answers she never confirmed that she would stay with the Channel forever. So if she later decides to leave, no one can say anything about her.
To say whether she would be successful outside Ch7, I would say very likely. She already has good acting skills, versatility and experiences. What is needed to have her career skyrocketed is a good storyline where she can show her skills to the fullest. I would love to see her working with OneHD, because a lot of their hit lakorns has ex-Ch7 lead. Noon started this trend with Pidsawat, who was a fierce competitor to Nakee. Then Baifern continued with Bai Mai Tee Plid Plaew, Mai with Wanthong, and Green with Krachao Seeda.