Is every Dhamma cause of suffering?
Is every Dhamma cause of suffering?

No: as mentioned in this answer, nibanna is classified as a dhamma (and as anatta) but not a cause of suffering.

The same source says,


  sabbe saṅkhārā dukkhā — "all saṅkhāras are unsatisfactory"


It's sankharas that are classified as unsatisfactory (and impermanent).



But the term dhamma is broad and can be used (in different contexts) to mean a lot of different things -- for example, Jayarava's essay on The Simile of the Raft identifies some of the different possible meanings of dhamma.