Just so everyone knows, I do not intend to go kitesurfing without any instruction at all. I was simply waiting to find the right instructor that wouldn't beat me over the head and try to upsell me on overpriced lesson packages. I've only launched my kite on the beach a few times and would not go into the water without proper supervision and instruction.
That is the right attitude - but it isn't right. You cannot know, but the most dangerous place to be is on the beach trying to launch a kite. This is why we react so strongly.
Please get the instructions first, then play with the kites - for your sake, for other beach users sake, and for the kite community that wants beaches to stay open for kitesurfing.
Just fooling around a little bit is actually so dangerous it can kill you or others and can close down a beach and call for general regulations elsewhere.
No matter how careful you are, you have not trained to respond rationally - this is done in the water where there is more room for error. Shit does hit the fan, it it does so regularly for beginners and also occasionally for experienced kiters - we are just much better at putting a lid on things before they become dangerous.
As to information sources: I do agree, except instructors are in a unique position to take you through hands on excercises, observe mistakes and focus on safety. Your friends will know how to surf, but will focus on getting you surfing, not on getting you to react safely to various unforeseen problems. I know first hand that you can tell a person ten times to do something, and they will do something completely different when they get stressed. Safe excercises on the water is the only way.