Starboard has come out with some new footstrap screws that are 7mm PT vice the previous 6mm PT (Plastics Tech) screws.
If you install the new 7mm screws, with a #3 Phillips screwdriver and use some soap as a lubricant, you will probably solve all your loosening/bending/breaking issues.
Not sure where you can get them, but they are std. on all new Starboards manufactured since around mid September 2009.
According to Tiesda, they will screw into the existing FS screw holes that accepted the 6mm screws just fine.
Lubricating the screws with a bar of soap, and using the correct #3 screwdriver has always worked nicely for me.
Never pulled one out, never broke one, and, after a couple of retightenings (from initial installation) they do not loosen up. I've had somewhere around 100 Starboards in my demo fleet over the last 10 years.
Hope this helps,