System Workbench for STM32

1) Setting the bit to 1 lights it up, 0 shuts it off. Any leakage current doesn't look like it's enough to turn it on.
2 & 3) I know neither of these should be related to what I'm doing, but I was curious to see if I was having any kind of effect on the GPIO pins at all. Strangely, I still see a high voltage on PA13 and PB4. You're right though, it shouldn't be anything to do with my program.
4) Again, you're quite righ, I've stuck a big delay in to check and it's blinking perfectly.

Well, getting there with baby steps.

Thanks,
James