I found the answer to #2 in this thread

https://forums.totalwar.org/vb/showthread.php?t=76357

Its in descr_events.txt

So we can modify the years it takes for certain events to trigger when we also modify the timescale.

For instance, if originally the game spans for 250 turns, since it is 2 years per turn, usig a timescale of 0.5 would make for a game play of 1000 turns.

But, the events being triggered by years instead of turns, will still happen at the appropriate historical date which can be 300 turns down the like for of of the first.

In my case I wanted to have the events run at a timescale of 1.0 while the turns run at 0.5, two seasons etc, but 300 turns can be long, and I am going to experiment with halving the years it takes for the events.

I understand that will offset them from their Historical Date, but on the other hand when we start a campaign we are not playing the real History we are playing an alternate History, no matter how historical the elementa making up the game are, as such dates can be alternate aswell..and fun is the main reason of playing this game, not rehearsing real history, but exploring the "what if" scenarion, even if it starts at a real historical setting, it diverges after we press the turn button for the first time :)

So only remain the question of building times..I supose I can just go back to 2.0 and start a campaign and see for myself.

I am asking however in the forum not only for myself but also for any future people that may come to this forum asking about these things I thought there may have been more than one area affected by changing the timescale in terms of gameplay, and having all information in 1 thread would be better than anyone trying to find bits and peaces here and there as I had to do.

:)

So I guess I'll be answering myself once again in a few :)