In some forms of Sufi medicine, something very like unto kabbalah is used for diagnosis and treatment. Not all forms, not in the pulses, but there is a tree of life of sorts (diagram of the cosmos to the Sufis), with stations (read: sefirot - even the planetary correspondences match Jewish kabbalah).
You can tell the station a person is at by their symptoms, and there are very gentle treatments you can use to invite the soul to get to the next station (I disagree with this mostly as I don't find kabbalah to be linear - I design treatments to get people about a quarter of an inch away from the painful place, if you will, so that the soul damage can heal - as to where they might end up next on the Tree - I wouldn't begin to guess). I'm trained in that, and use it. The reason language wasn't a huge stumbling block when I was learning even though my Arabic is pretty weak is because the names of the sefirot (stations), souls, all of it - it's almost identical from Hebrew-to-Arabic. I didn't need to even look up the words - seeing the diagrams and hearing the terms, I knew exactly what they were about.
Though the Sufis use - 11.
I'm not terribly sure if it's the mathematics of the thing, or the philosophy underlying the mathematics, or if they had to change it just a bit to make it a little different.
My guess is that the gematria and numbers play very little part in it, ultimately. Which is why I'm not keen on gematria - it always seemed like a distraction to the real thing.
And as to the person who said it might've been safe a long time ago - Sefardi Jews have always used kabbalah - we didn't lapse out of it for hundreds of years or anything, and texts are still being written. The Ashkenazim, not so much, but they didn't lose it either - it just wasn't as popular because they were western and 'rational'. And the Sufis, because they sort of came into being in the same time and place as the golden age of Sefardi kabbalah - they've always used it.
Can it be dangerous? If you use it for personal power, yes. If you use it to understand and apply God's mitzvot to your life, and to heal - well, I suppose any spiritual path can be dangerous. You may find yourself forced to do things that you might not want to do (like stopping gossiping about people or not hurting them). That kind of thing.