1 - It is my understanding that you want wider angle more than telephoto when shooting from a plain. A combination of motion sickness (even from those who don't normally get it) and loosing track of what you're trying to shoot (with you and the plane moving.)
1.5 - weight is the big issue. If you are going to take pictures on foot (it sounds like you are), I would suggest at least a mono-pod if not a tripod. Obviously the mono-pod is easier 'cause it's smaller and lighter, but it isn't as good as a tripod. VR is nice, but real support is better.
2 - I would try to reduce it to as few as possible. That leaves more room for other things (food/water being high priorities.) Something seriously wide angle, I have the 17-40 f4 L and its an amazing lens, but I'm not sure that is wide enough for mountains and temples. I use it as a fall landscape lens (foliage not mountains.) Sigma makes some in the 12-15mm range (not that zoom, but something in that area as the starting point of a zoom.) I don't know how good they are, but really wide angle wide angle is not easy to find. I'd check out some review sites.
3 - The 70-200VR is an amazing lens from all I've heard. A little big, but not uncomfortably so. That would be a good reasonably close wild animal lens, it sounds like that isn't your focus. It sounds to me like you need something wide angle more than more zoom. Unfortunately Nikon doesn't seem to make an f4 version of that lens (without the VR) which would be cheaper and maybe fit your price range (with a wide angle to boot.) Since you asked the 1-lens question it sound like you need one of the wide angles.
4 - Since I'm not on a mac, I'd go with the Epson. I don't know how well the ipod works for image storage, I just know you can do it. Make sure you take the power issue into account. Extra batteries (and always charge them whenever you can!) are a must.
5 - My dad has the LowePro Orion and likes it. I have the biggest toploader there is and its nice for what it does (I carry the 100-400 in it) it has basically no space for anything else. So you wouldn't have easy access to the other lenses (if they were in a separate backpack with other gear & food.)