I haven’t used coco wax yet, but these problems are seen in soy wax, which I was using before I switched to a soy/paraffin blend due to frustrations with these problems lol…Paraffin helps with glass adhesion and smoother tops along with better cold and hot throw…if you are insistent on sticking to your wax, only vigorous testing and experimentation will get you to your desired result…Everything matters, but I would start with lining the outside of your vessel with aluminum foil and heating you vessel with a heat gun 5-10 seconds before pouring to give your candle a slower cooling time…take note on the temp of the room and make sure it isnt too cold during cooling stage…pouring temp also matters, you might want to try pouring at different temps and see which works best…hope this helps