You'd need to reverse engineer the ign barrel & its circuitry and come close to a pinout to enable the features you need without having you to use the metal stalk/key.
Your fob has built-in RF... as I understand. Now whether Porsche encrypts the signal, your guess is as good as mine but if not, it should be easy to sniff the frequency using a cheap Made in China $39.95 RfID sniffer and program something out of a micro-controller with 2 or more 12volts relays.
Love that start btn idea, Go Go Digital
