The tape is how they seal the membrane to the outer lip. my slide has the same tape and has a peeling edge that has not peeled any more since new. the peeling is only about 1/4 inch and to me is normal. if you want cut off what is peeling carefully so you don`t cut through the membrane.
Yes the slide looks like it needs to be adjusted. never done it before, so I can`t offer advice on something I`ve never done! sorry.
The bubble in the membrane is either from the adhesive not holding or worse case, the adhesive failed due to a water leak and wet wood. push on that spot with your finger tip. it should be solid like wood, not soft like rubber.
Good luck!
