I'm not sure what study the author was refering to but the current opinion is that there is no increase in the risk of adverse consequences in persons with MVP. For a recent article on the prevalence and complications see New England Journal of Medicine Vol 341; p 1- 7;1999.
I researched the questions you asked quite extensively prior to my surgery and came to the following general conclusions.
1. There is a higher incidence of sudden death among those who have MVP but there does not appear to be any casualty. i.e. the mpv is not the cause of the sudden death, it is commonly related to HOCM or arrythmias and people who have these conditios seem to have a higher incidence of mvp. however if an individual only has mvp there is not a higher incidence of death. This is a case where the statistics don't tell the full story unless they are investigated.
2. Most people feel better with exercise rather than without it, even if you have mitral regurgiation. The person you spoke with may have been confused about mitral stenosis (where the vavle is constricted) in which case exercise is generally prohibited. Exercise with stenosis could be dangerous but usually exercise with regurtigation is not.
3. Prior to my surgery I lifed weights 2-3 times per week, rowed competitively 4x per week and did additional exercise 2-4 times per week. The mitral regurgigation limits the ability to perform at maximul level but the exercise itself was not prohibited. My cardiologist indicated that he would prohibit some activities such as scuba diving where if a mitral valve rupture occurred, it could be fatal because the person might not get to the surface in time. My cardiologist generally felt that even if the mitral valve ruptured, (a conditiion seldom seen) I would not die but would require relatively immediate surgery.
4. Talk to a cardiologist and if they can rule out the other items which might cause sudden death, you can relax even with MVP and even with some regurgitation. You might need to take antibotics before any surgical procedures, including dental teeth cleaning.
Goood Luck