Sufism does not clash with other Islamic branches enough that it should be curtailed. Many people have a negative view of Islam and the several branches but sufism is not that much radically different. It would be hard for a government to determeine what branches of a religion should be curtailed and which should not.
No, it does not clash to the point there it needs to be gotten rid of. People are always going to fight over religion, and nothing is ever going to change that, since people have different beliefs and faiths, that a lot of the time conflict with othere peoples beliefs.
The idea that a belief system can be 'curtailed' is presumptuous of the human identity. The only way to 'curtail' a belief system is to oppress it. If Sufism is such a threat to other Islamic branches, perhaps the other Islamic branches should evaluate why. Does Sufism provide its followers with something they do not?
When it comes to religion, there are always going to be sects and cults that spin off from the original faith however it was intended. You do not simply curtail one of the branches or sects. This is cause for violence, and besides, it's all just interpretation of an ancient book.
No Sufism does not clash with other Islamic branches so severely that it should be curtailed, because the Sufists think that they are the purest form of Islam. The Sufists believe that their philosophies of existence pre-date religion, but other than that, there is nothing so different about them that is incompatible with the other branches of Islam.