One question that I have is how to get a tool kit through security at an airport with all the changing rules etc. Of course if I was inclined to check a bag it would be a lot easier but I typically travel with just a carryon and a backpack.
I've got a small RadioShack Leatherman tool that I carry everywhere except when I'm flying. This tools is small enough that you could probably fit it inside the iFixit tool bag. Of course, RadioShack doesn't carry it anymore but it looks a lot like the Leatherman Squirt. I've got the version with wire strippers but there's times I'd rather have the pliers...
Of course, I could purchase a bunch of tools individually, but then I'd have to think about things and I'm a bit short of time. (If I were to go this route, which tools would you suggest as a minimum set?)
Don't forget a magnifying glass, and maybe even a head-mounted LED flashlight.
It seems to me there is no ideal toolkit. I travel with two knives similar to the one you lost and I have often wandered which Leatherman I should request for a birthday present, but none seems ideal. I also have one or two utility screwdriver/flashlight combos given away at trade shows and a Gerber Solstice plus a set of adaptor plugs.
However Murphy's Law seems to dictate that whatever you take with you, you will never be able to MacGyver the tool set to do what you want. When I was in South Africa now, I needed a hammer drill, concrete drill bit and a socket set.
The ideal tool kit is a local resident who has a full set of tools.