That bike's not a death wish. In fact, since we're talking about a frame that is actually designed to accept an engine, it is probably safer than a typical motorized bicycle. Especially one with a 212 engine, as some have built (and I am considering).
And it's no more difficult to put good brakes on a minibike than on a MB.
I do think the OP would do well to consider spending a bit more for the extra large frame
. It would make it an easier build.