There are really no problems with the footstrap screws.
If you get the 6mm Plastics Technology (PT) x 28 mm screws and install them correctly, using a regular
#3 Phillips screwdriver, lubricating the threads with a bar of soap, and retightening after an hour or 2 on the water, the screws will last the life of your new board.
Also using a vice or vice grips to compress the K9 locks up into the footstrap webbing so the screws get a good start in the insert is recommended.
If you receive the newer 7 mm x 32 mm PT screws, and install them correctly you will have no issues beyond they are very hard to install the first time.
1/ Take one screw out of the footstrap, lube it with soap, and screw it (bare) down into each hole you intend to use for your footstrap positioning. You don't need to let the screw "bottom out" but just screw it in about half way to put some threads (like you would with a tap in a piece of metal) in the holes.
2/ Compress the K9 locks into the footstrap webbing using 2 pair of vice grips or a vice of some sort.
3/ Lubricate each screw with a bar of soap before installing.
4/ Retighten all you footstrap screws after an hour or 2 of sailing the board.
As to foostrap positioning, that depends on your size (height and leg length really) to get the spacing between front a back straps the most comfortable.
The you need to decide how tight you want the straps on your foot.
Some like them tight on both sides of the foot, others (like me) like them spread out at least one hole
wider than standard so I can turn my foot a little to apply pressure to the boad with my heel in different positions.
Then you may want to try a couple of different positions, in different conditions, to see what effect it has on the board.
I normally set up all my demo boards with the back strap rear screw in the middle position and the back strap front screw one hole forward of the middle position.
For the front straps, I put the outside screw in the back hole in the outboard positon and the inner screws in the middle position.
Seems to work pretty well for the majority of demo riders.
Hope this helps,