In terms of "emergency", I would be surprised if your network provider doesn't have arrangements with the local providers in the countries you mention, even if you have to pay exorbitant rates. Except for mainland China, I don't think I've visited any county with zero connectivity for me.
Infrequent texting in my experience is not expensive, certainly less than a US dollar per text sent, and free to receive.
Data charges are another matter.
The U.K. network "3" has a pretty good system called "Feel at home", where roaming fees are not applied in many countries, including several of those you mention. But I am unsure if it can be easily set up while outside of the UK.
If like me you need to be reachable on your usual number then local SIMs are not an option. But if you don't, then buying one at the airport and disposing of it as you leave is probably the easiest route to go down. Of course some countries impose restrictions on how readily SIMs are made available, so it's worth checking in advance.