Cheers Johnman,
In our company the Flight Plans normally come with a recommended Block Fuel figure depending on which airports are being used. This is not always the case, but the reason is mostly the cost of the fuel. I guess this is more likely the case on short/medium haul flights. Otherwise, as mentioned by some others, we discuss the days variables and then decide (together) which MIN Block we'd like. Obviously the captain has final say as he/she carries the ultimate responsability. At our company, nobody will (to my knowledge) ever say anything if we fly around with "too much" fuel.
I can't think of any pilot who has ever worried about solar/cosmic radiation, but then again I've never spoken to Concorde pilots.
We do have monitoring, but not to the same extent on all fleets, but here I also know too little about what gets monitored and not.
The other question you had about REF Codes...
If you know the number of touch-down stripes, you can deduce the length of the runway. A bit theoretical, seeing that not all charts will give you that detailed info:
1 (stripe)= less than 900 m
2=900-1200m
3= 1200-1500m
4= 1500-2100m
6= 2100m or greater
BTW: this is just crude info
Kind regards