I'm not deciding what to do with other peoples money and I am not threatening anyone with violence.

We decide these things together through the democratic process.

I know it is hard for people like you, who reject democracy and any kind of power anyone could have over them, it must feel terrible to not be able to escape a system you disagree with. But I also think that on the spectrum of systems we had, it is not really fair so scream "taxation is theft" and "social security is immoral" at democracy, if you consider what we had before.

The threat of violence enforced the system that let them get the money (with a democratic government's name printed on it, mind you) to begin with. Was violence immoral when it enforced a system that shaped wages and the returns of capital in such-and-such way?

violence only enforces contracts, which are formal promises. Violence doesn't enforce market rates for wages, demand and supply and other market forces.

Is this in your ideal system? Because that is really far from being true.