Really, you should only care about Islam? What about the merging of Christianity and Islam? Would you be concerned about that? There are a few mega church pastors trying to that very thing, calling it Chrislam. Now granted Rick Warren doesn't advocate killing but the Muslims, who believe that Jesus will return and convert into a muslim and tell his followers to do the same, will preach that people who do not covert should be killed. When Christianity is watered down and tried to be made into something its not, there's only an evil result.
When people are deluded into thinking Mormons are Christians, they open the door to other kinds of false teachings and beliefs,.
...therefore leaving themselves open to being baited and witched to all maner of false belifs and practices.
The New Age Spirituality is always waiting on the sidelines to scoop these people up once they've been deceived by mormonism....interesting is many in cults and false religions have had time within the mormon church before they fall into the cults etc.