Yes you can try other ingredients.

Wax - You can try other waxes but just be mindful that the hardness of waxes can vary. Beeswax for example is much softer (and of course it's not vegan). So you would need to adjust the receipe.

Oils - If you don't want to use Camellia oil, you can substitute for any type of liquid carrier oil. For example, Almond, Jojoba, Strawberry or Sunflower are great options.

Butter - You can also use Mango Butter in place of the Shea Butter. Cocoa butter is a harder butter so you will need to adjust the recipe as the butters can have different consistencies. 

Essential Oils - you can use an alternative essential oil but ensure you check dermal limits and that it is safe to use on the lips.

Yes you can leave out the essential oil. To ensure that the receipe adds up to 100%, just add the 0.5% to the oil.

Yes you can use a different essential oil. Just ensure that your chosen essential oil is safe for the soft skin on the lips and check the dermal limits.

This formulation is best suited for a moderate climate.

In a cool climate, you may need to reduce the amount of wax slightly.

In a hot climate, you will need a higher amount of wax to keep the balm solid.

You might need to play around with the ratios to find the one that suits your climate.