I have cut over 500 lips with the router setup in the video and have had very few problems it. The biggest issue that I have is, if I use a piece of Lexan that has a lot of excess material around the edges of my template, it wants to grab it more. I solve that problem by keeping the excess to a minimum. Another minor problem is, after you cut several lips, your tape starts to lose it's "sticky" and your Lexan will shift. Just replace your tape regularly and you won't have any problems. I don't find that the templates are "tippy".
As far as for your safety concerns, it is mildly unsafe. But as Vic stated, keep a minimal amount of the cutting edge of your bit exposed and you shouldn't have any problems.
Gene