There's a download button after purchase at the top of the page on the main page. You can redownload the different files from there. 

Update your drivers, then try the "Can My [system] Run It" under "Download demo".

If you right-click on the name of something, there is an option to edit the name. 

There's actually a certain amount of money it costs, ranging from 1-3k, but it's just not displayed in the game (at least not for me on the browser version)