Should you be bold enough to ask to overstep the 10 minute boundary
10 minutes is easily enough time to get your point across. Any longer and boredom could set in. Genuine interest from their side will dictate the total length of the presentation.
A presentation should have a good start, a good middle and a good end. The bits in between take care of themselves.
Definitely run it live, show them the real deal, gain their confidence by getting them to participate. Get them interested in it.