The answer to all of your questions is YES YOU CAN ; )
About the Driving aids and AI configuration just think about an rFactor and there you have it, quite aggressive AI, difficult to chase and huge ammount of setup and aid customization.
The feeling of the trucks are great, near the best mods Ive seen in rFactor. Anyway, dont compare it with rFactor 2 as this last one will give you more chances to install mods and drive other categories. But if you like truck races, Formula Truck is a must buy.
Hope it helps, good luck!