1) No, you’re applying the correction in the wrong direction. QNH is below standard at 950hPa so at FL130 on QNE == 1013.2hPa you are not much over 11,000’ QNH, well below the terrain. Looking at it slightly differently, at sea level the altimeter would read 1,900’ / FL019 if you set 1013 on it, so it is over-reading by 1,900’ relative to the actual height of the terrain; with 13,000’ indicated you’d actually be at 11,100’.
2) There’s not quite enough information given - it’s considered normal (legal) to plan to land with some fuel on board and that is included when you’re checking against MLM. Need to know a bit more about the different elements of the “fuel” as this could affect the maximum traffic load.
M&B will never catch on ...
Yeah, it exists, but I’ve never heard of anyone actually using it...