Sorry, forgot that I said I would do this.
Here you go.....
Hard to be precise, but taper seat appears to be 61 degrees.
I am assuming they measure the thread length from the bottom of the taper, making the stock bolts about 32mm, but I don't know this for sure. A CSK bolt/screw length is measured from face of head, to tip (ie, overall length), so I really don't know. Those Titanium bolts are quoted as 28mm, would be nice to see a rule next to one.
EDIT: picture shows, thread is 28mm to bottom of taper, so they're probably ok, certainly for stock wheels without spacers.