You describe a couple issues, but don't know if they are actually caused by the several problems I see with your code. So I can't answer your points #1 and 2. All I can do is point out the problems that are caused by not understanding the way data flows through a LabVIEW block diagram.
1. You have two separate event structures within a while loop. The problem is that only one will run at a time. The loop won't iterate again until the other event structure has a chance to run.
2. You have buttons outside of the while loop. They are only read once at the beginning of the program. They should be located inside the appropriate event structure so that when they can be read and actually reset.
3. What are you doing with the For loop? Why do you have it iterating 5 times to feed X Y pairs to the graph.
4. You are using local variables. You almost certainly have a race condition that is compounded by the problems with the duplicate event structures in parallel with the For loop.
5. Several of your event cases Lock front panel until the Event completes. That in conjunciton with #1 causes your program to lock up. You hit a button, the front panel locks up until that event completes. But that event can't complete until you hit a different button to allow the other event structure that is waiting to execute and allow the loop iteration to finish. But you can't hit the button needed because the front panel is locked. A regular catch-22.
See the attached VI for a much simpler version that actually works.
