TVS diode for surge protection: how does it works beyond Ipp point?
1) no, your source is an ideal voltage source. Every source in the real world has some series resistance. So in practice less current will flow but often still enough to blow the TVS.

2) Not on its own. When the TVS reaches its limits, what options does it have ? It can only blow up and then either become an open (so now your circuit will get the overvoltage and be damaged !!!) or become a short, more current will flow, the PCB tracks will vaporize.

You need to do something to make the TVS survive !

Solutions are: input series resistors to limit the current. At the maximum expected voltage the TVS will conduct and the resistors will take all the voltage so make sure they are rated for that.

Another solution is a fuse which will blow and disconnect the input.

The best solution is a combination of a fuse and a resistor. There are also resistors which can act as a fuse.

If you can guarantee that there will only be short overvoltage spikes 
at the input then the resistor only solution is enough. Fuses are slow so for fast transients they do nothing.

Key point is that you need to dissipate the energy of the spike in a controlled way. Resistors are ideal for this.