Yes these are both possible....well at least the 2nd one is a for sure.
1) I have heard about this and it does involve deleting a section in the map file when you open it in wordpad. However, because I have never done it because I believe it removes certain things from being able to be on the map I am not sure which section you must delete.
2) To make a powerplant give off more power simply add the thing below into your map file while having it open in wordpad then edit the Power= tag to however you see fit. The current ones I have on there are what they would normally give. The following in order are, GDI power plant, GDI Turbine (the add on to the GDI powerplant), the Nod Power Plant, and Nod's Advanced Power Plant.
CODE
[GAPOWR]
Power=100
[GAPOWRUP]
Power=50
[NAPOWR]
Power=100
[NAAPWR]
Power=200