RE: Starsurfer holes on bottom
Are the individual screws longer than the holes are deep?
Did you measure the depth with the screw (with a washer under the head of each screw) mounted through the strap.
The thickness of the strap, and the additonal washer between the head of the screw and the strap should "space" the length of the screw so it's slightly less deep than the hole in the insert.
No, the screws are not supposed to "penetrate" the insert, but I think you will find that with the corect washer and strap thickness this isn't going to be a problem.
If you think it's a problem, add another washer under the head of each screw.
Also, use a small nail or something that's the same diameter (or slightly smaller) than the root diameter of the special 25 mm PT screws.
Hope this helps,