Couple items, first off I'm not in love with STEAM. I've hated the whole idea of STEAM since Half Life 2 first came out, I detest any type of product activation or copyguard which makes life complicated for the legit buyers.
That said, the way Railworks is currently set up is tolerable. Buy Railworks, create a STEAM account and log in, activate the product once and that's it. Railworks comes in either download or boxed versions, I have the boxed version and installed, activated, then put the disk away for safekeeping in about an hour. One problem they used to have was "game currently unavailable" when you tried to play it, so most people set the launcher up for offline mode until a patch was announced. Latest STEAM update eliminates the need for that, if the STEAM server is busy or your internet connection drops out, you get a screen saying you're not connected and you can start the game offline anyway.
So the majority of the objections to STEAM have been eliminated, the major ADVANTAGE to STEAM is you no longer need to back up all the default files - if you screw up one of the default routes or scenarios just delete it, run the "Verify integrity of game cache" utility built into STEAM and it will download whatever the latest version is of what you're missing.
If you want to stay with railsim instead you're going to get left behind because a lot of future stuff won't be compatible.
So. With all that out of the way, try this;
http://railsimulator.com/en/railsimfilesDownload and install patch mark 1 and mark 2, and also get the RSDevTools Installer and install that. Next go into your Rail Simulator folder, find the RailSimEditor.exe file and RIGHT click on it, select COPY. Go to your desktop and RIGHT click on an empty area, select PASTE SHORTCUT.
For that shortcut you should be able to run railsim without the EA download manager or a key disk, essentially it's a legal "crack" because RSDL themselves removed all the copy protection from RailSimEditor.exe. Good thing, because I also had the download version of railsim, and after my email address changed I sent three requests to EA customer service with no reply.
To merge the versions, what I did was installed both in different folders, then used RS_Tools from
http://www.rstools.info/page9.html to package the York Newcastle route from the European version, then installed that into the US version. Then I copied the \Assets\Kuju\Railsimulator folder from the European version to the US version, NO to overwrites so I got only the files that were specific to the European version and left out of the US version.