Before we go any further - a standard disclaimer: Laser projectors can cause serious eye injury (including blindness) as well as thermal burns to the skin. They can also damage digital still-image and video cameras, as well as certain types of video projectors (mostly DLP projectors). Any laser operator should be very familiar with the safety concerns and legal requirements surrounding lasers and laser projectors before they purchase, install, or operate any laser equipment.
Also, the laws governing the use of lasers in public differ greatly depending on which country you are operating in. I honestly don't know what the laws are in Sweden. But most countries require at least some equipment certification, while other countries also require the operator to obtain licensing or other approval before using lasers or laser projectors in public. Before you get too involved with this new project, I urge you to research this topic thoroughly so you understand the legal requirements and safety regulations.