In Emulators / NES ROMs

Is it possible that not all (official) games that ever came out for the NES are available for download? Why is there no "Shadowgate (G)", for example? I'm definitely sure that Germany had a translated version. It's the same with "Darkwing Duck"? Where's the "(G)" version?
So, if there are some missing games, what can a person do against it? Who actually converts them into PC files? And how is this done?

There is a modification for the NES called CopyNES that you can get. There's a guy on the NES World forums that's getting ready to distribute them. You send him your working console, and he ships it back to you ready for action. You can also check the NesDev forums for it too. This will allow you to dump NES ROMs. He's also including a debugger in it, too. It looks like a great project, and if I get enough money I plan on picking one up. You can also get the stuff to do it with shipped to you. So if you're hardware savvy you can do it yourself.

If there's such an equipment, why are there actually bad dumps? Shouldn't it work in the same way every time?

Do you know who dumps the NES ROMs, so that they appear on the websites? Because I don't want my NES to be rebuilt. But maybe I could buy the missing games on eBay and then send it to anybody, so that the games are downloadable. But it of course has to be a reliable person. So, who's actually responsible for all those NES ROMs on the big sites, like ROMNation.net, ROM-World.com and EdgeEmu.com?

The reason there are bad dumps are most likely from not knowing the software being dumped. I'm pretty sure you have to know the size of the chips involved and what-have-you. Certain things like the size of PRG, CHR... if it uses CHR-RAM as opposed to NES ROM, etc. Dumping them with the wrong "dimensions" (if you will) will make a bad dump. You still have to know what you're doing in order to dump a game. I don't