I believe it's rare that people run away and never return, but it does happen. It would be interesting to know more about her inside relationship with her family.
As you can see from all of my posts on this thread that this is one of my "pet" cases. I spent several months researching Ruth's disappearance, and I've posted a lot of info on this thread regarding this case. If you will read through all of them, you might find answers to some of your questions.
Ruth's relationship with her family from all accounts was very good. She came from an upper-middle-class family, lived in suburb outside of Cleveland, Ohio, was a good student, and had gotten engaged shortly before her disappearance. She appeared to be a "normal" college student, very involved in her sorority. She had been studying for a test just before her disappearance. She had complained to her family about being under stress to get good grades, but what college student hasn't felt that way before?!?
I'm not sure where the info from regarding the purchase of a suitcase, as this is not something I've uncovered in my lengthy research. From what I've learned, she did not take much anything with her, and there was no suitcase purchased by her any time close to her disappearance.
The remaining big mystery to me is who called Ruth prior to her disappearance. Her sorority sisters claimed a man called for Ruth on at least one occasion, and that the voice was not that of Ruth's fiance.
My first thoughts were (1) Ruth was pregnant or (2) she became involved with someone her family would not approve of (or both).
Throughout all of my research over many months, I've started to think that perhaps Ruth HAD become involved with someone other than her fiance, maybe the "mystery man" who had been phoning her. Was this a married man, perhaps?
I'll post more later with my reasons for suspecting that.