No AI settings in World Tour mode. AI settings are adaptive to how you play in that mode. Since you are just in year one, you have a ways to go before you start getting more challenging AI. It's way early in the game. It's like GT5 in that is starts out easy, and isn't until late in the game career that it will become more difficult.
Bogie answered it perfectly. I am currently level 21 or 22. As you level up, they get MUCH more difficulty. The AI difficulty reminds me a LOT of GT5. Starts out very easy and gets VERY hard. Sometimes too much like the GT5 AI where they just stick to a racing line and dont avoid you.
The career (world tour) is the only mode you cant adjust the AI. You can adjust it in Auto Vista, Private Multiplayer, and the event playlist.
I'm only into the third season, but based on FM3 I'd expect longer races later on and I can already say that the seasons get longer, just as they did in FM3. From what I read in the past, the career mode will be several seasons longer than FM3's. (In FM3 you could play beyond season six, but seasons seven through infinity were just season six repeating.)
I can also say that the AI seems to be pretty well maxed out for me by the time I got beyond level ten. Their cars, at least in regards to the front-runners, run every bit as fast as what my car does, they don't seem to brake too early or too much, and they don't seem to make mistakes like overshooting a turn or spinning out.
... But I think the races later will become longer...
