The idea behind putting the newer tires on the back instead of the front (if you are replacing a pair of tires out of sync) is that it is easier to correct for understeer than oversteer. You have ZERO control over the rear wheels in a FWD vehicle. You have both steering angle and brakes/throttle to control the front wheels. If you have the deeper tread on the front wheels and you lose traction on the front wheels, the back wheels were already out of control. There are plenty of videos detailing this.
FWD vehicles usually have a tire rotation pattern of front straight to back, back cross to front (such has been my experience with FWD vehicles). The exception to this is if you have directional tires (think Goodyear Assurance tires with triple tread - the type that has the large V-pattern groove). Those types of tires are designed to channel water away from the center of the wheel (the point of the V hits the ground first, forcing water into the channels and away from the tire). If you put them on backwards, it will reduce traction, potentially causing hydroplaning. In that case, you rotate straight front to back, no crossing (unless you have the option of remounting and balancing tires at home, but that will probably reduce tire life by added wear on the sidewall, not to mention a higher chance of damaging your rims every 6-12 months).