So, last clearance is : cross xyz at 11000. I am now 10 miles from xyz at 13000 and atc clears me to another waypoint further down the arrival without giving me any altitude restriction.
Shall I stop my descent at 11000 eventhough the waypoint is not on my route anymore ?

Other case, atc now put me on a heading without specifying another altitude.
Still 11000 altitude applies ?

"say altitude restriction"....

The altitude restriction applies to the waypoint, if you are given an amended route that does not include the waypoint then the restriction doesn't apply.

So if I was given a heading, I need ATC to give me a new restriction, or if They give me a waypoint on the arrival, I just have to follow the arrival then.
Right ?

A vector effectively cancels the STAR so any restrictions will no longer apply.

If you are then given a waypoint on the arrival the controller, if requiring you to re-intercept the STAR profile, should say something like "proceed dct xxxx on course", at/after that waypoint, any restrictions would apply.

A few years ago Nav Canada published an RNAV phraseology guide that may help.

http://www.navcanada.ca/EN/products-and ... eology.pdf

Thanks !