To answer your questions:

1. It'll depend on the thickness and type of the leather, some are different to others. Work the strop with your hands, this will help soften the leather and condition it. You can also apply Fromm strop dressing to condition the leather.

2. Rubber cement is best. Glue the little flap down with rubber cement and then, once its dry, sandpaper over it with a high grit (I use 1k) sandpaper to make sure the area is totally flat and smooth. The condition with Fromm strop dressing.

3. This will depend slightly on your beard type. Thicker beards will pull more, but if the pulling is uncomfortable then you need to get the razor honed.

To that end, I recommend getting the razor professionally honed in order to ensure that you have the best possible edge.

4. This shouldnt make any difference!

Good luck!