Tell us about yourself!
Yes, send me the error message. Could be that the newer Arduino versions aren't compatible with this old sketch. I'm good at debugging this type of problem.
Yes,6 lanes is just like make 2 - 3 times more. Although if you are new to electronics it can be frustrating and you might want to build two lanes before trying something more ambitious.
One more point, eventually you will run out of input/output pins on your arduino if you try to scale up too much (you will need 1 input and 1 output per lane). But 6 lanes is fine for most arduino boards (you typically have 14 digital pins plus the 6 analog pins can also be used).