If I'm reading this correctly your biggest and most recent problem is that he is throwing dishes away with the food. The natural consequence for me would be to take the plate and cutlery away and give him bites a few at a time like I do with littles. Similar to when I'm teaching them to sit at the table and eat from a little plate instead of a high chair tray. If he can't act appropriately I would take away the choices where he is choosing the wrong thing (throwing the plate away).
As for getting him to eat....you can't. BUT you can minimize the stress for yourself by not allowing complaining and perhaps setting a timer for mealtimes. I had a super picky, super disruptive eater for years. I decided several months ago to stop caring if he ate or not and to aid me with that I started setting a timer for meals and snacks. He HATED not being coddled, coaxed and badgered to eat and hated it even more that we stopped sitting at the table for long periods of time. When the timer buzz's I dump the plates. He eats much, much better now. Mom and Dad set a timer at home too and it works for them as well. He was controlling all of us and we took away the control by stopping him from dictating meal length and taking the focus totally away from him and his food. It might work for you.
