[DarKCroNo]

Your problem is that your not toggling your buttons, we had this problem too in labview. If you look at the wiring, u said that if button 1 is true than such happens (set motor speed) but that action is within the case box, and it only executes if and only when button 1 is true. The only time button 1 is constantly true is if ur holding the button. Try holding ur buttons and see if the motors are moving the way u'd like.
Now if that doesn't work, i don't know if its also the values ur inputting to the motors which are affecting it but... when I was programming it i didn't realize u cud put values -1 -> 1 to indicate full speed rev and full speed forward, and so i used 127 and -127 and i'm not sure if that makes a difference. Because I tried 127 first i don't know if thats the default pwm values for the program to read.

Now about the limit switching, I have just finished a program where for our robot, a gate will be drawn up and down to let balls roll out of our basket. We used limit switches to trigger the stoppingmotion of the gate. I wouldn't mind giving it to u if you want but the problem is I don't understand it much to explain. I spent a whole night doing it and got it working through debugging, but if you were to ask me how each block works i would have no clue haha...
Oh and I can give you a toggling vi as well if you'd like.

If this gives you too much trouble there is another thing you can do which makes it a whole lot simpler. Since your motion is rotating you can use a potentiometer and use a PID control loop to control how it spins... but i guess if you constantly want to spin left u can't since theres a max and min value for a pot. You can also try an encoder, I dunno much so just suggesting.