How do I set the governor and set the fine controlls for it?
Also, can you have Solar Plant, Coal Plant and Nuclear Plant all in a city, or can you just have one plant (or two)?

One more thing, can you turn off the map grid? On the main (or maybe map preferences) it has an option for it, I've tried using that as well as [Ctrl] + G but it doesn't seem to work.

1. just right click on one of your citys and select contact govener or something like this form the menu
2. just 1 plant per city
3. don´t know, never had the grids i think

Yeah, CTRL + G is how you turn the grid on/off. I do it all the time. Not sure why it wouldn't work for you.