For your first problem. Does the function pushBlocklandWorkbench actually exist? Could you show us the function? The keybind is trying to call this function. Also, most people let the user bind their own custom key to things with this:
$remapDivision[$remapCount] = "Keybind Category";
$remapName[$remapCount] = "Keybind Name";
$remapCmd[$remapCount] = "functionName";
$remapCount++;
For your second problem. Are you sure chatInput exists? Are you calling the sendBWChat function? Are you sure the value of chatInput isn't just blank? Also, I'd suggest naming the GuiTextEditCtrl with a prefix to prevent another mod using a GUI element with the same name. Something like BLWorkBench_chatInput maybe?