Ignore whoever told you that. Try to find someone who can give you an honest fitting or get you on the range to try out a few options. The shaft is the most important part of any club, and age and swing speed are only 2 of many factors in determining the proper shaft.

You don't mention any issues with your current driver setup (hooks, slices, shot dispersion, etc...), so I guess the reason for someone suggesting you change your shaft is your distance off the tee. The proper shaft certainly has an impact on distance. Were you fit for the head/shaft combo originally? If you were, then unless it's your fitter suggesting a change, you shouldn't change. If you weren't fit for the combo originally, then you should go through a fitting.

Ditto. Go to a reputable and experienced Titleist fitter in your area. Always visit mine when considering new equipment. Am 75 and he always comes thru with the right setup for my Titleist equipment. Still swinging in the low 90's. I really like the Fujikura Speeder shafts.