I think it's all right to carry DSLR bodies and L lenses. It depends on the countries/places you are traveling to. I'd say safety is key. More often than not, it's because photographers let their guard down which causes the gear to get stolen, and not so much because a Canon has higher resale value than say a Nikon so chances of it getting stolen is higher.
Whether to bring lens A or B also depends on how "on" you are when you travel. It sounds nice when you are here but once you are there in the foreign country, with the hassle of traveling itself (think getting to places on time, rushing for public transport while having to bear weight of your gear and changing lenses!), you may dampen your mood to take pictures.
Between 70-200mm and 135mm, for versatility, I'd go for the zoom. But if you want creative shots, have time to walk around, then 135mm will make a difference to your shots.