You could add some RFI suppression and a 100-500ma fuse to the 5V line from the USB, but otherwise the PIC should be fine. Also bypass the PICs power rails with a 0.1uF cap.
You should add some resistors to limit the current to the Opto's LEDs. What are you planning on driving with the Opto's transistors?
I also notice that the keypad common line is connected to Vdd. It would be easier to connect the common line to Vss and use the PICs internal pullups. Otherwise you'll need pulldowns on PortA if you leave the keypad common line connected to Vdd.