What is the difference between normal and difficult levels?
These are my guesses - Intelligence SI or my team is getting tired faster?

There's no difference intelligence wise. The difficulty is a coefficient that gets mutliplied to the riders' normal stats, and you can see the coefficients in local.cdb, under sta_race_difficulty.

Normal leaves the stats as they are, a rider with 75 AVG will remain a 75 AVG rider, but he'll become a, say, 76 AVG guy playing with Hard. Of course, your teams' stats remain the same, it's just the AI's riders' stats that change.

That's correct, I remember Freire just making it completely clear in the beta forum 2 years ago. Above 6 or 7% - I'm not completely sure - in a TT, the TT stat doesn't matter anymore.

Coming from PCM 2014 Sad I'm a little bit confused with the training system.

In PCM 2012 we had stars to see how a rider can progress in a skill.
Now I see numbers like "5-7" which I understand as general progression notation. Can I still see details progression level per skill as before or not any more?

Once we know the rider style (i.e. "Modern"Wink do we have to simply assign to him a "modern" coach and then we never change this or am i missing something?

thanks a lot