What would happen if Israel annexes ALL the Israeli 'settlements' in the west bank ?

This is one of the variants of actions Israel warned the PA about if they try to declare the "palestinian state" unilaterally. This will mean that the Palestinian Authority decided to denounce the Oslo Accord of 1993, and this will leave Israel with two options.

1. Annex all the areas in Judea and Samaria it considers necessary, first of all the areas with the Jewish majority, and leave the PA some isolated and unviable anclaves. This will mean the fast political death of the Mahmud Abbas ´Fatah and its substitution by Hamas in Judea and Samaria .

The second option is

2. Occupy the entire Judea and Samaria including the area currently controlled by Arabs and with the Arab population, and return to the situation before Oslo, when Arabs in Judea and Samaria had the status of residents and could work, live and study in Israel but had not the status of citizens with the right to vote, and when they had not any form of the political independence.

Both variants will mean the dissolution of this strange thing named "Palestinian Authority".

Which variant Israel will choose will depend on the concrete situation in the concrete moment.

It will be just another violation of the International Law (like East Jerusalem) and Palestinians will outnumber the Jews, which means Israel would no longer be Jewish, but Palestinian Arab, just like before 1948.

They can not do that

But if they annex the whole of West Bank Palestinians will rule

Palestinian population will be 4 millions + (almost 50% 0f total Israel population)

Death and destruction will continue until a settlement is reached with all factions of Palestinian freedom fighters. UN and US can help reach this settlement as the road map is already there.