Career Mode is great but I'd always recommend playing full matches as well where you control the whole team. I love creating leagues and playing as England. To just limit myself to Career Mode would be... well, limiting. I'm not saying that you are. I too am looking forward to Career Mode but some people play it exclusively. I don't think that I'd buy the game if it was Career only.
I hope that when you're getting signed by overseas teams it makes clear which matches you're going to play for each (At the offer stage) and if you're creating a crossover by signing for multiple teams.
I'm looking forward to bedding in and playing some big First Class innings, maybe One-Day too but my interest in Twenty20 continues to evaporate. I don't just want arcade cricket smashing the ball over the rope all the time. I want demanding real Test like innings and grinding out big big hundreds, doubles, triples... that's the motivation!