First, I was not surprised of that sudden marriage. Rene has been trying to get married for yrs. I felt she was in love with the idea of marriage. Now that she's gotten the taste of marriage, she'll think twice the next time. The very worst person type to marry would be a popular rock or country singer. Those groupies at all concerts and the one night stands by the rockers is well known.
Since Rene is a regular type person, growing up in Katy, TX with non-hollyweirdo values...she'd not put up with an on the road rockers lifestyle.
In the end, Rene will marry a non type hollyweirdo man...and live happily the rest of her life. Rene has actual grass root values similar to FReepers. (Also, her success did not start on the couch as many successful women actresses.)
I'm not as optimistic as you about her mental ability to adjust to a normal life. She appears to like the spotlight and seeks out guys of high visibility. One of the reasons for the successful marriage of Joan Woodward and Paul Newman was their ability to blend into suburbia and separate themselves from the Hollywood set. RZ doesn't demonstrate that same ability, although many of the Nashville set seem purposely set on doing just that.
All in all, I vote for his ability to sustain a long-term marriage to the right person more than her ability to adjust to everyday life, particularly if children are involved.