Portability is not an issue with the Playstation, you put it under your TV and you don't move it anymore, it's not a Switch.
And how is the life of the console an issue? Are you saying liquid cooling or a vapor chamber would shorten the life of the hardware?
Says you. I bring my PS4 on trips if the occasion calls for it and when visiting family. One of the main reasons I'm a console gamer if the fact that it's plug out, put in a bag and carry without complications. Switch is the same deal unless you bring your dock with you or buy after market accessories.
Your other question has been answered and it's a yes.
You are missing the point. The PS4 was not thought with portability in mind. You can move it around if you choose obviously but it's not what it was made for.
Now I'm no specialist of those cooling techniques but how are vapor or liquid cooling systems that would be inside the machine make it less portable? If you can move it around as it is now I'm sure you still can move it around if it has a vapor cooling.
Also about the life span of a hardware with vapor cooling I would imagine that if Sony would choose to implement such cooling that they would work the system so that the life span of the console would not be reduced significantly. The Xbox One X has vapor cooling implemented and I haven't heard anywhere that the console dies after a short time.