Multiple hi temp problems

I know this might be heresy on this board, but I am seriously starting to doubt certain BGE componets ability to withstand hi temps. I absolutely love my egg, but as you will see I have some significant problems with it.

Last night, we did pizza at dome temp of 500-600* using the placesetter legs down. I mostly filled the firebox with lump and left the vents open until dome temp hit 600*. While I expected this to torch the gasket (which was already mostly gone anyways), I had a number of other problems.

First, there was about a 1/4" to 1/2" gap btw the dome and base that emerged when the BGE was at max temp. I believe this was because the metal component connecting the top and bottom parts of the spring assisted band expanded due to the heat. The result was the dome was pushed up and backward resulting in the gap at the rear of the dome. During the cook, lots of smoke and heat escaped through the gap leaving the black metal band covered with white residue. I checked this morning and gap is gone once the unit was cool.

Also, found out this morning that another piece of the firebox cracked off (it is now if four pieces and barely holding it shape). Another crack btw the air holes on the firebox also emerged so I expect future seperation. Even the fire ring has crack in it, but for now it is in one piece.

If that wasn't bad enough, the metal fire grate which cracked into two pieces previously now is has several new cracks and will be in multiplte pieces soon. Even worse, the grate now is far from level and is significantly bowed downward. It now is barely serviceable.

I guess the temp below the placesetter far exceeded the capabilities of the egg. I guess my qustion is should one do a hi temp cook with the placesetter at all? Is it better to do pizzas and such with legs up (although I worry about cracking the placesetter using this approach)? Has anyone tested the max safe temp in the firebox before these types of problems start occuring? Based on my experience, it seems one should keep the dome temp at least below 500* when using the placesetter.

I realize my broken parts are under warranty, but I think I have lost my original proof of purchase. I am thinking about contacting the mothership to see if they will honor the warranty anyways. Otherwise, I just might have to do a complete (and expensive) refurb myself on my on dime.