u can try doing the following.
go to microsoft flight simulator x -> SimObjects -> Airplanes -> feelThere PIC A343CFM
then open a file called Aircraft.CFG
scroll all the down to [jet_engine] then change the thrust_scalar from 1.5 to 1.3.
This should be able to solve the wobbly issue and the decelerate problem. however the downside is that it takes longer to accelerate to your selected speed esp. in high altitude.