If PIN5 configed as PIO0_5 , can reset through this pin?
If pin5 configed as PIO0_5, pin5 configed as pio0_1, can entry ISP mode?
If you re-configure the SWD pins they can no longer be used for SWD. ISP is the only way to get back in.
JTAG is not able to access the debug port on the LPC8xx.
There up to six available IO pins on the LPC810
You can use all six pins on the LPC810, but you lose three of them when debugging.