Hi rich49!
To answer your questions:
1. Yes, the levers do 'click in' when you reach a detent and
2. yes, you have to use pressure to get them out of the FLX detent.
But when you move them towards the next detent, the levers do not move automatically to it. That way you can move the levers like in a conventional airplane.
Generally:
The thrust levers can only be moved manually. They move over a sector that is divided into four operating segments and has five positions divided by detents or stops. The thrust lever position is transmitted to the FADEC, which computes and displays the thrust rating limit and the N1 for that Thrust lever angle.
In autothrust mode the levers are set in the CL detent. They do not move even with a power change by the A/THS. The max. range for the A/THS is from idle to max. climb power (both engines). But the max N1 rating is limited by the thrust lever angle. I.e. if you set the levers somewhere between idle and CL, the max. N1 that canbe set by the autothrust system will be the one corresponding to that thrust lever angle you set.
Hope this helps a bit.