Your response to the issue of cosmetic surgery is somewhat confusing. As I understand it, a bride is veiled by her groom at the wedding so as to show that he is not marrying her for her physical beauty, but for the beauty of her soul. Is there another understanding to Bedeken that I am missing?
The halachic reason for the Bedeken is that this intimate act where the bride allows the groom to “dress” her, is already the beginning of the marriage. Like by many issues, once a custom or mitzvah is instituted, many additional symbolisms and reasons, like the one you mentioned, are suggested to enhance and embellish understanding and identification. For example, some explain that it’s for reasons of modesty, so that the participants shouldn’t gaze at the beauty of the bride, obviously dressed attractively, who is in the process of becoming a married woman and “off-limits” to others, while others add that it commemorates Rivka’s covering herself with a veil when she meets and marries Yitzchak, Breishit 24, 65. In addition, as I wrote previously and as every married couple knows, the physical attraction between man and wife are not only desirous but totally necessary. The Living Torah is very practical and pragmatic (unlike the Catholic approach), knowing that this beautiful Godly magnetism is the “oil” that enables the “apparatus” of marriage to function well. To improve your suggested explanation, I would suggest that the Bedekin may also symbolize that the physical beauty or attraction is not the most important part of the soul-mate relationship, but we definitely don’t see it as something negative or undesirable.