Dosha is not something mysterious and doesn't indicate fear for life or other misgivings. Mainly It is not about death. Dosha represents two things, as explained below.
Rahu - Ketu Dosham is meaningless. There is no need to worry about Rahu-ketu dosham. But Psychological match is more important than any Dosham. If the couple have better understanding about each other kindly proceed with the marraige.