How to avoid Fasting during Ramadhan (Suggestions for ex-Muslims in closet)

(1) Number one advice is to eat and drink, but if caught then tell them immediately:  Ahhh! I FORGOT that I am fasting (and spit whatever in your mouth, and try to run to the water tap and show that you want to clean your mouth and you really regret forgetting it.

(2) Fake a severe headache. Fake an upset stomach. Fake a fainting. Get confirmation from the doctor that fasting is not safe for you.

(3) If tap water is safe, then drink it while doing Wadhu. If not, then there are small bottles with filter. Keep such a bottle in the bathroom in the name of using filtered water for washing your teeth and toothpaste.

(4) If you are a girl, then make excuses for prolonged periods. 

(5) If you want to eat too, then "Jerky Meat" (or pemican) should be your first preference (in US/Europe), as even a small piece will give you a lot of energy. In India/Pakistan, you may buy "hunter beef". In Arab countries, you may buy (Arabic: الخليع)" which is a dried meat too (mostly available in Morocco). Another option is protein bars, which could help you with hunger in small amounts too. Try not to eat such things which could make you thirsty. 

(6) Tarawih: There is no solid suggestion how to skip it. Nevertheless, one option is to fake a Food Poisoning, and vomiting directly in the mosque, in open, in front of everyone, especially your family. Moreover, you have to vomit after Iftaar couple of times after eating meal at house too. 
Faking a vomit is much easier than faking an upset stomach etc. You just need to take more salt and you are ready to vomit. And as compared to upset stomach, no one is going to doubt you after vomiting while everyone could see it from his own eyes.

(7) How to avoid getting up early in Sahar?
Just eat food at Sahar, and then take big amount of Salt, and vomit after the fasting has already started. Tell your family that eating times have disturbed your stomach.

PS: There are other ways than salt too for faking a vomit. Use the Youtube videos for this purpose. You have to vomit in the open (in front of your family) once or twice. Rest, you could run towards the bathroom, shut the door and make noises if you are vomiting, and then flush the water. Your family will still believe you.