Improving flat feet - stretch series?

I'm one of those guys cursed with flat feet, although this is more pronounced on my right foot - and what this means is that breaking into sprint or moderate load on one leg regularly leads to a sprained ankle. I did see a specialist a few years ago, who said that I had weak calves and that I should do simple straight calf raises on a daily basis. As a typical young man, I did a few sessions then quit when results did not magically materialise. I'm now wiser and older (this is up for debate :D), and understand that things take time.

I know that flat feet can be connected to other structural issues, such as weak hips and inflexible ankles, so with this in mind I've purchased the Front and Middle splits stretch series. So my questions are:

1) Do you think these stretch series might help with the flat feet issue?

2) Are there other parts of GB that might help?

3) Do you have any other exercises or advice that in your experience has helped you or others?

Strengthen your plantar muscles with special exercises, do balance work on instable surfaces, and go walking bare feet on natural ground for a regular basis.

I've had aging tennis players clients with horribly flat feet. Besides calf raises, improving the mobility and everything that Foundation/Stretches will give you, I made them do the "short foot" exercise. Google it, you'll find videos on Youtube…  Also other intrinsic foot muscle exercises, such as opening/closing your toes, moving your big toe, crunching towel and similar works well. My worst flat-footed student got his feet in a pretty good shape. It takes time. 

Dekuji Suzanna Didn't know the name of the exercise in english! ("short foot" exercise)

Thanks for the responses guys, it's much appreciated. I'll give these things a go on a regular basis