All I wanted to ask what happens if you fly in dreadful weather with absolute legal minimum?
Good question. Firstly, dreadful weather rarely "just happens", it is normally forecast and sufficient fuel would be carried to divert to somewhere above minimums. Also bear in mind that the weather requirements at an alternate are more restrictive than at your destination. However, if you do find you are flying on absolute minimum fuel in flight you make sure that you have more than one plan. You'll be thinking about Plans B, C etc. and make sure they are always viable and capable of immediate execution. By this I mean you listen ahead to what is going on at your destination and your alternates, constantly keep up to date with the actual weather and have rough (or accurate) plans of headings, lowest altitudes, expected approaches and have some sensible fuel planning numbers. Then as the flight progresses, ensure you can continue towards your destination. As soon as your destination becomes out of limits you immediately execute one of your standby plans.
In other words, apply common sense.