You can use flax seed meal or xanthan gum instead of psyllium husk powder. It will have a slightly different texture but will still turn out great. If you use xanthan gum cut the amount in half
The water to coconut flour ratio can vary depending on what brand. Some flours are more coarse so they need more water other flours are more fine so they don't need as much water. You have to play with it a little depending on what brand of flour you use.
The best substitute for psyllium husk powder is finely ground flax or chia seeds. If you do use xanthan gum you will only need half the amount of xanthan gum and it may effect the texture.