*Please could you tell us what you like about your son? What you love about him? So far, we have had hate, frustration, disgust, disappointment.
What is it about him or his achievements that makes you smile, feel proud, admire, celebrate? Do you tell him or show him these positive feelings you have about him? Do you ever just give him a hug just because?*
Why should she justify herself to strangers on an internet forum? She came her for help but, true to form, a snarling pack (not sure as to the collective noun for MN'ers; a vitriol?) of people made her feel worse. I can see a lot of frustration. Nothing more.
@OP - I'm sure you don't hate your son and venting on the internet is a good way to blow off some steam and get rid of the frustration. Of course something needs to be done about the stealing but it also seems important to get to the root of the issue be it bullying, an eating disorder or any other reason; it's pretty serious. You've realised his shortness will be an issue and have tried to tackle it so good for you. Intentions are undervalued.
In my very frank opinion:
I think that discussion with him will do some wonders. Reassure him. Perhaps even minimise the stealing to get to the real root of the problem.
When one child is being difficult, we may favour the other. It can be hard not to even if it's simply spending more time with them while the other's grounded, for example. Maybe looking for a fresh start is a good idea!
This isn't the headmaster's fault. My OH is one and going in all guns blazing and looking to apportion blame won't get you anywhere. He isn't responsible in this case.
Your comments re. organic diets etc sound a bit mental! I'm all for healthy eating but within reason. Maybe a more relaxed view would help. Weight management is as simple as calories in vs calories burnt. Is he a fussy eater? Look at low calorie filling foods like broths, soups and grains. Have you spoken to a professional about his health? Are they concerned?
As I'm sure you know, parenting's a balancing act. Allowing him to fit in with his peers (within reason) goes a long way at this age.
Treat your sons equally. My mother did so to an extent we tease her about it now, but it meant something at the time.
I'm sure it can be frustrating when you parent two children and one has issues the other doesn't and you can't see why. Keep putting the effort in; it'll be rewarded.