Can I Think Healing Thoughts at Other People?

No.  That is New Age garbage that has nothing to do with Christianity.  Jesus said to go preach the gospel to everyone, not think the gospel at everyone.  If you want someone to get healed, tell him what Jesus did for him and offer to lay hands on him!  If he won't receive it, trying to override his free will by thinking thoughts at him is witchcraft and therefore sin.  You can pray for the person, of course, but your faith cannot force something on someone who doesn't want it.

No one in Scripture got anyone healed by thinking healing thoughts at him, so that practice is contrary to Scripture.

In fact, the same can be said for muttering “healing words” under your breath.  Your words need to be understandable to the sick person to be of any value.