Try memcpy(node_to_node,node_2_nodeCopy_i,sizeof(node_to_node));

int node_to_node[9999999]; creates an uninitialized array of 9999999 integers.

You can create as many nodes as you like until your stack is full which will crash your game.

When a function was started the program will only jump to the following function/instruction after the current function is completely done, that's correct. If your function takes a lot of time your framerate will drop because acknex has to wait until all your functions are done to render the image to the screen.