This is why I said have the option, so people can choose if they would want it enabled or not. It hardly becomes any more spyware than any automatic update software about, and you could choose to enable/disable it.
Do you know what information limewire sends when you actually have it open? I would think if you trust it enough to use it at any point it wouldn't be much different to use it on startup without the load of the whole program being opened if you chose to have it enabled..