While I agree that on its own, Thaumcraft is a very balanced mod, it wasn't really meant to be used in conjunction with other mods. EE and buildcraft make it much too easy IMO.
No because we can provide quantifiable proof that the moon is not made of cheese. If we could not, we would have no reason to doubt your hypothesis. That is where the difference lies.
This is just as bad as fundamentalists hating people because they aren't the same religion and I take offense to it (even if I am not religious). I would cool it before you really offend someone.
It is the firewalls provided by Windows that are the problem. Turning them off to download one file that you know is safe will not compromise your computer. Turn them off, download the launcher and the mod packs, then turn them back on.