Well technically, yes you are spending the devs money by using the forum. The hosting isn't free, and more posts = more required bandwidth.
But that's not the point.
The point is that demo users have no right to demand more from the software,
because they have not paid for it. Would you go to a garage for a car, ask them to fit a new engine, lights, CD player, sunroof, AC and alloy wheels because you
might come back and buy it in the future? I don't think so.
The demo has 4 possible track configurations (ignoring the car park) and 3 different cars. It's not time limited and you can play it online. That's not bad for free. And you expect the guys to work on more content when they're getting nothing back from it? Doesn't sound fair to me.
The S2 licensed people have paid their money, lent their support and played the full game. They know what it has and what it needs. Therefor they are the only ones qualified to ask for more.
The damage system and sounds are not an issue here - everyone has that, irrelevant of license, and we know that they're still a WIP.
However, there is no doubt about the hostility of some folks towards demo users, especially those asking for more. Maybe they should be a bit more tolerant, but you have to see their point that time spent giving content to non-paying users is time taken away from working on content for the people who have paid.
Hardcore LFS players are very protective of their product - try not to piss them off