Looking at the schematic and the firmware sources, I can't see any problems using 2 different LEDs and another SW2 connected in parallel (if I'm wrong, please correct me). But I can't see any way, to put the BOOT1 signal in to another switch. It's connected to PB6 and there is a definition in the firmaware SW, but no reference. Is that correct, that BOOT0 (or SW1) is hardwired into the chip? Or is there a chance to use another pin in parallel with the same effect?
I'm using axocontrol, so I guess, I can use PC0/PC4/PC5/PB6 and PB7. They seem to free.