1)Any time i try to hold iron bars in my hand the frame rate drops to around 3 fps until I un-equip them, also when breaking already placed iron bars the causes the game to lag.

IMPORTANT NOTE: DO NOT TRY TO DESTROY THE CRYSTALS WITH THE IRON BAR CAGES AROUND THEM IN THE END, WHEN IT BLOWS UP IT WILL MAKE YOUR GAME CRASH AND YOU'LL DIE AND YOU WONT BE ABLE TO RETRIEVE YOUR STUFF CAUSE EVERY TIME YOU GET NEAR THE AREA THE GAME CRASHES AGAIN. NOT COOL

In other words don't try to kill the Ender Dragon unless you can do it without destroying the crystals that have cages around them.

2)maps are currently broken for me, when i make a map the texture is glitched and invisible and it says its already at zoom level 4/4, this also applies to when you put it in a item frame