I hope JM can give me some advice about "cutting" double eyelids.
What I do is liposuction and thread embedding. You can go to a big plastic surgery hospital. My eyelids are swollen. It will be natural after I finish it. I suggest you bury the thread.
As for the inside opening, you can wait for the double eyelids to see the effect before deciding. If the eyes are short or far, you can open them. But this one has a scar, be careful!