A few questions

[Garnier]

What dates do gunpowder and the compass become available? And are there any other events that can be used in "27 Invention requirements for building Label" in the build_prod?

And also, is it possible in some way to make buildings not get sacked and destroyed when you take a province? This severely hurts the AI's teching ability since whenever they lose their provinces they go back 20 some years of buildings..


And another question, after I start a campaign, is there any way to tell which difficulty I chose? I intended to choose expert but have forgotten.. I'm not sure anymore..