For the crepes- Recommend using a medium to medium-low flame, like pancakes, crepes take time and you don’t want to burn them by using too much heat. Also, I always tilt and rotate the pan immediately after pouring the batter which helps it to spread out evenly across the pan. Letting them rest overnight allows the gluten to relax and results in a light more delicate texture, read here for more info
For the orange butter– You want the butter to remain creamy, if you think it’s too thick consider adding a tsp. of orange juice to the butter.
For the flambe– you could also turn off the stove and use a match or a fireplace lighter, make sure to have at least a 4-5 foot clearance above your flambe pan, since the flame gets big!
Find it online: https://www.alldayieat.com/recipe/classic-crepes-suzette-rum/