AFAIK the Slashdot editors didn't censor your posts, as they can still be seen on your user page, along with here and here. However, they might have decided that it wasn't good enough to be featured on the front page, as happens with countless other submissions. You might disagree, but that's just how Slashdot works: curated content.
As for the supposed impossibility to post that story anywhere, it was posted on Reddit and actually made the front page of the Technology subreddit. Soulskill even gave his point of view on the matter in the comments. I don't know where you see that conspiracy of yours, but I don't see it at all.
Copyright and trademark are two different beasts. Copyright allows you to control who gets the right to copy your work. As such, you can give out licenses, for free or for a fee, since its purpose is exactly that: being able to profit from your work. Whether aggressive copyright enforcement is the best way to do that is a whole other story. =P
The purpose of trademark is not the same at all. Trademarks are used to protect a brand's image. They are issued to prevent brand dilution (the brand becoming a generic term, as happened with Kleenex) and brand confusion (somebody else passing a lesser product as a better known brand, hurting the latter's reputation). Because the intent of a trademark is to preserve the uniqueness your brand, you are not allowed to knowingly let someone else use it. If you did, it would weaken any later trademark claims you made since you'd have permitted others to make your brand less unique. This is why Jack Daniel's says they are forced to send the cease and desist letter.
Regarding whether this is an American thing or not, I do not know. I think it also applies here in Canada, but then again IANAL so I can't say for sure. =)
I hope this helped!
reddit is really a collection of sections pertaining to different subjects, called subreddits. As such, your experience on reddit will vary wildly depending on which subreddits you subscribe to, as they each have difference themes, rules and degrees of moderation. For example,
So if you want to see if reddit can be interesting for you, my advice would be this:
First, go to this page, which lists which subreddits you'll see on the front page. If you have just created an account, you'll be subscribed to the default subreddits. Look at the posts in each one and decide if you want to keep seeing content like this. If not, click the "unsubscribe" button near the top of the sidebar and boom, it's gone. Just this step will generally increase you reddit experience greatly.
Next, you can search for a topic and look at the subreddits you find. If you'd like to see more, subscribe, then search some more until you feel that your front page contains stuff you're interested in.
That's pretty much it. I like that system, but as with everything, YMMV. =)
Nobody else is doing this at the moment with Linux, except for Canonical
Not exactly true. Desura would be a good example of that.