I dunno about adding such command because... Cheating.
1 - Does It fills in the direction of the arrow? It should be going from Gray to Yellow.
2 - I have to check that out.
3 - You mean Exp Rate? It should increase exp rate from killing monsters.
As for the option that makes monsters that scale to your level, It is intended that they give their original exp regarless of their status boost. The option is just to not make the game boring after passing the biome level.
Yeah, it doesn't. It goes from Yellow to Gray.
It does increase EXP gains, but not by all that much, once you get to the later levels (which for me is around 4.2K).