You are so wrong that I think you might be a Troll, but I'll bite anyway.
where of course you assume that the person who had the money in the first place really deserved to have it.
Whether or not the person deserved the money, the government forcibly takes the money away. Whether or not the person deserved the money is up to the person who gave him the money, not to the government or you (thank god).
but a lot of persons today earn money without doing any useful work (e.g. they work for advertisment - creating artificial needs)
It's useful to the people paying them. Advertising can also inform people of solutions to their "real" needs. I'm not quite sure what an "artificial" need is.
or by doing harmful work (creating weapons, destroying the environment, etc...) or doing no work at all (just cashing in on their portfolio).
Weapons for self defense, no one runs a "destroy the environment" business, investing provides capital for people who produce things. These are terrible examples and are what make me think you're a troll.
the reason why some can earn a lot of money for nothing is in our system of society. this is an artificial system of laws and rules and it allows some to take the money from other persons without giving them anything useful in return.
Actually, the government is pretty much the only group that can force you to give them something without getting anything useful in return. You don't have to pay money to advertisers, weapon makers, or any other individual business unless you choose to.
so taking the money from people that have that money because of some artificial rules by an other rule (the tax system) is just one way to try to compensate the many faults of the capitalist system.....
You are implying that a fault of the capitalist system is that it is "artificial". That is silly. There are many faults of the capitalist (or at least the pure free market) system, but the fact that it is "artificial" is not one of them.
Your name is attached to your post. You don't need to add it again.