I'm pretty familiar with Intellectual property issues, so what I offer is merely information, a restatement of the rules, so to speak. No legal advice is given or warranted.
The rules for copyright, while there are distinctions among jurisdictions, are becoming more streamlined b/c of international conventions. The rules I speak of are the U.S. rules, but their genesis is from British law, so there should be some overlap. However, I am not familiar with british law, and so only the British statutes can tell you exactly how copyright is defined, how infringement is defined, and what liabilities exists for potential infringers.
Generally, though, once one has purchased a copyrighted material, one has the right of personal use. In the U.S., this means you can do what you want with your purchases. If it is miniatures, you can paint them, you can improve them via flocking, these being generally encouraged. But you can also melt them down and make candlesticks, if you want, and you have the right to resell. (such as is done through Ebay, garage sales, etc.). This right is usually, however, asserted only as a defense. Now for my continental friends, there is a qualification called "Moral Rights of the Creator." The creator is, in this instance, not the almighty, but likely to be the corporation that employs the sculptor, the sculptor or molder having assigned his creator's rights to the corporation in exchange for employment. Moral rights dictates that even if you buy the work, you cannot do anything that materially alters the artists' creation. You couldn't buy the mona lisa and add a moustache for a nice improvement. Moral rights are not recognized in the U.S. as of now. As far as your hypothetical of adding "fake" and selling, this wouldn't really protect you, because your intent is to infringe the copyright by making exact copies of the miniatures, and selling on the market. The legal presumption is that you are trying to displace the copyright holder's interest in the market with his own goods that you've wrongfully misappropriated from him. In addition, at least in the U.S., those that encourage or help could be liable via a theory of "inducing infringement." I don't know if this is so in U.K, or if it is under another name. Now, one way around a copyright in the U.S. is through "Parody." Again, not sure if this is accepted in the U.K. But theoretically, one could take a miniature, and make it completely absurd, by making fun of the copyright holder's original work product, and you could get away with this. We see these all the time, i.e., Wierd Al Yankovic is the ultimate example of parody. To qualify, "Parody" must be somewhere on the item. This way around the copyright will likely fail if it is just a replica of the item with "Parody" stamped on it. It has to be intended to make fun of the parodied item.
As to references to the LRB, again, one generally has the right of personal use. House Rules might be qualified as fan fiction, and so long as one isn't selling for profit, these will likely be ok. Fanatic, from what I've seen, expressly encourages this. One may quote from another work, provided due credit is given. Think back to papers in school, or any other work where quotes are given. But you can't plagarize. A webpage with pics and other fanfiction generally seems proper in this context, but the legal status can be tricky. There is something called "derivative works" and the copyright holder, at least in the U.S., (and I think in the Byrne convention, the internationl standard for copyright), the copyright holder has a property interest in these too. So I know some holders go after those who create their own stories with copyrighted characters, (i.e., Paramount is pretty vicious when it comes to individuals using Star Trek characters in new stories posted on the net). I wouldn't be suprised if Fanatic/GW went after someone who usurped Bob and Jim and put them in a new story. There are alot of arguments that could go both ways.
Finally, as to submitting ideas to the company, this can be contentious. Cases upon cases abound in which individuals make suggestions to companies, and when companies use the ideas, and not pay for them, suits ensue. Generally, because these ideas are submitted uncopyrighted, or if they are mechanisms, unpatented, it is like giving the company a free give away, and whether one is compensated or not depends upon the discretion of the company, which, I'm sure most will not be surprised, usually decline to offer money for the generous idea.
Whew! Hope that helps with information. Again, jurisdicitons will differ as to time of protection (highly contentious in our Supreme Court this term in the U.S.), scope, and liabilities. But the general rules, if I remember correctly, are generally these.
Obviously it goes without saying that making a profit from other people's /companies creativity and output is morally despicable, but was interested purely in the legalities, as it's a field i know very little about. As i am thinking of submitting some of my own game concepts to various companies in the New Year, issues such as copyright are something that i really need to brush up on if i don't want to risk getting stung...
