
Your pup is obviously food motivated, allthough it seems like a battle at the moment you will find that you can use this to your advantage.
My 'pup' is now 13 months old, he is highly food motivated and a couple of months ago he started to steal food at any given opportunity. I had made plans long before getting my pup as to how I would train him and make sure he was the 'perfect' dog and I was quite proud of how things were going - imagine my horror as my 11 stone Mastiff barged his head onto the counter while I was making a sandwich and stole a block of cheese (and swallowed it after only 1 chomp)!!! That was it, he realised he could steal food so I had to up the 'security' while food was around :(
Firstly he is never left unatended while the kids are eating, allthough I'm a stong believer in the 'pack theories' and I am confident my dogs know thier 'place', I am also aware that dogs are oportunistic and will do what they can get away with. Stealing food is self-rewarding, evey time the dog is succesful at a theft atempt of food it is another step closer to becoming a habbit, so you need to make sure that the opportunity to steal isn't there in the first place.
Any attempt to steal food is met with him being shut in the kitchen in his own for a few minutes to calm down (he generally tries to steal food when he is exited, it has nothing to do with hunger).
A few weeks of trying to stay one step ahead has really started to pay off, the only times I really have to be carefull is when there is cheese or bread about as he'll steal it of the side if he's by himself.
I have always got my pup to 'work' for his food, but this entails him having to follow a few commands before his bowl is placed down, it helps get the message accross that obedience=food, his bowl will not go down unlss he is paying attention and doing what is asked.
Several short, fun training sessions throughout the day may help by giving your pup a mental work out, if they don't help with the food stealing at least it helps with building trust, bonding and obedience :)
As for your pup being a nightmare to walk - try a halti, they give you so much control over the head it is unbelievable. My pup was a nightmare for walking past people - he wanted to play with them & jump up, with a harness and a halti on, along with some treats for distraction & reward it worked a brilliantly :)
I also have 2 children (9 & 10yr old boys) and a husband who is not commited atall to training (the deal was if I wanted another dog, then I had to make sure it behaved!!), my boys were scared of the pup to start with, however, once I proved how well-behaved the Mastiff could be with the right attitude (calm, patient & consistent), they all started to copy what I do so now I have 'helpers' and my boys are not scared of him (even though he waighs more than both of them put together!!) :)
DONT GIVE UP, you haven't done anything wrong, your pup is just being a pup. The more work that you put into him now, the better the dog he will grow into, so don't feel like you've failed, feel like you are ready for the chalenge and look forward to what he will be like when the hard work has paid off :)