I recently spent two weeks in Italy, had a blast, shooting every day and used less than 80 gb. Shot in raw, no video. But I also had plenty of extra cards on hand just in case.
I don't have any experience with iTouch but have used the Mobi Wi-Fi cards successfully. They send images to your device wirelessly if you can't wait to get home to start sharing.
As for weather, it can't be that hard to look up average temperature and precipitation history online, if you're that worried about it. Earthquakes... seriously? How often do those happen and how would you prepare for one anyway?
You're taking both cameras? In that case put a standard zoom on the k5 and take the 15mm and 100mm primes for the K-01. That will give you lots of options without having to change lenses all the time. The 28 is pretty close to the 35 and if it's raining, you'll be glad you have the weather sealed kit lens on a weather sealed camera covering both those focal lengths and more.
I'd just take one camera (and several lenses) but that's me, I prefer to travel light
and fast..