There are a few seemingly simple points about this (which are actually very complicated, once you think about it for a while):

1) Temperature is a bulk property. It relates (roughly) to the average random (internal) kinetic energy of a system. By random I mean not correlated--a bullet moving 1000 mph has a lot of kinetic energy, but all the parts are moving at very nearly the same velocity (same speed and direction). A cup of hot tea can appear to be stationary, but each of the molecules within it can be moving at 1000 mph in a random direction.

But there is more to kinetic energy than just molecules moving around (translation energy). Molecules also have rotational energy, vibrational energy, and electronic energy (this last one doesn't really apply unless we get to very high temperatures).

2) There are many, many (MANY!) water molecules in a pot of water. I mean, mind-bogglingly many! Imagine a pot of water with 1.8 liters (kg) of water in it. It contains more than 6x10

^{25} molecules of water (that's about a million times as many stars as there are in the visible universe...)

So one can easily confuse themselves by going back and forth between thinking about bulk properties (like temperature) and individual molecules, or small numbers of molecules (like less than a few trillion). The best way to avoid these confusions is to think about distributions (

https://en.wikipedia.org/wiki/Boltzmann_distribution) Because we stipulate that molecules are moving randomly, there are some that are moving really fast, some hardly moving at all, and everything in between. This distribution describes the proportion of molecules in each state (speed). And because there are so freakin many molecules, even the most bizarre things happen. Think about it, if each molecule has a one in 10

^{15} chance of doing something at any given moment, then in a collection of 10

^{25} molecules, there are (on average) about 10

^{10} molecules doing that very weird thing at any given moment. (think about that a while)

3) Finally, equilibrium is another bulk property. Single molecules can never be "in equilibrium" it must always be a collection (usually >10

^{12} molecules) that can reach equilibrium. What equilibrium ultimately means is that conditions are just right such that for every molecule doing one thing, there is another molecule doing exactly the opposite (or for every group of molecules doing one thing, there is another group doing the opposite). Imagine two rooms adjoined by a single door. If the number of people going from room A to room B is the same as the number going from room B to room A, then the number of people in each room stay roughly constant. Even if only one person can fit through the door at a time--then the numbers will oscillate a little bit, straddling that equilibrium (think of it as a dynamic equilibrium).

Vapor pressure equilibrium is established when the rate of molecules going from liquid state to gas state is equal to the rate of molecules going from gas state to liquid state (and yes, it is silly to talk about a single molecule in gas or liquid state, but bear with me...). Because the rate at which molecules go from gas to liquid is dependent on the number of molecules in the gas state in a given amount of space (the density of the gas, which is essentially the pressure of the gas) there is a relationship that naturally arises in which: if there are fewer molecules in the gas state than this equilibrium pressure, then evaporation happens faster than condensation; if there are more molecules in the gas phase than the equilibrium pressure, then condensation happens faster; the system will automatically shift until it has reached equilibrium again...

So what does this all mean for your question?

Will the water molecule break the IMF during the increasement or after the increasement, at the moment when the energy (temperature) reached the next level (i.e. reaching 90.0002C)?

Let's say in example: an increase from 90.0001 will break 20 water molecules from their IMF while an increase from 99.9999 to 100C will break alot more water molecules from their IMF? And thus the vapor pressure reaching the external pressure.

A tiny increase in the temperature of the water will lead to a disequilibrium, where now slightly more water molecules are leaving the liquid for the gas phase. This will continue until the pressure of gaseous water increases to the point where they are back in equilibrium (with now a slightly higher fraction of all total water molecules in gas state than when it was slightly cooler).