having a play with xplane

Hi guys

I have a couple of quetions that I can't seem to find the answers for at the moment,so I wonder if anyone can help.

I've had xplane 10 for a while but have not really got to grips with it due to lack of time and prefering to use p3d.

Although I still use p3d I want to use xplane more so while the issues with p3dv3.3 are on going and orbx,I've decided to try getting to grips with xplane.Although I have no bought addons at the moment and only using the default aircraft,I cannot seem to find how I would setup my x55 throttles to work on a 4 engine aircraft I've tried to add throttle 3 and 4 on the axis section but it only recognise's it for throttle 1 and 2. what I want to do is use one throttle for engines 1+2 and the other for 3+4 can some point me in the direction of how to achieve this.

Also I don't know if it just me,but although I have set all my controls set ok,when I use the cessna 172 and advance the throttle the aircraft pulls quite violently to the Left,presumably due to engine torque,however on becoming airborne it the banks very sharply right to the point of being uncontrolable. I tried it in a twin engine aircraft and everything works as normal,so i'm guessing its not down to my saitek x55 stuff or my settings.Any ideas on this or do you think its partly due to being a default aircraft.

Thanks