Since I'm the person who started this thread, I thought that I'd reply. Like you, I came to the Mac from Windows and the Rainlendar icon initially drove me crazy. In time, and after using a Mac for a while, I think you'll change your mind; but I absolutely understand where you are coming from. The best thing is to experiment a bit and find what suits you best.
The "LSUIElement" value should be the last one in your info.plist file. It's there; you don't have to create it. What app are you using to edit your .plist file (that might explain why you can't find it)? Apple's Xcode is the best, but UltraEdit also works fine.