all these bad stories about cue makers makes me wonder why nobody has put together a simple written contract (and maybe they have, but I just don't know about it because I've never dealt with one) when they do things like this.
Having a contract doesn't mean that this stuff won't happen, but it does provide you some level of protection. You could build in contact clauses, attempt to put some sort of time frame on things, etc.
Personally, I'd use a written contract if I were sending a high end cue off or paying a ton of money for a custom cue. And, I think you would be surprised at how inexpensive getting a contract drafted by an attorney can be. Now if you go to Jones Day or some mega firm that bills at $500 per hour, that's a different story, but a local attorney can fire one off in less than an hour and probably do it for a small flat fee. Not only that, once you get one contract, if you do this type of thing often, it's not that hard to modify it a little bit for reuse in similar situations.
just a thought