Lately I have been thinking of application security and binaries and decompilers. (FYI- Decompilers is just an anti-complier, the purpose is to get the source back from the binary)

• Is there such thing as "Perfect Decompiler"? or are binaries safe from reverse engineering? (For clarity sake, by "Perfect" I mean the original source files with all the variable names/macros/functions/classes/if possible comments in the respective headers and source files used to get the binary)
• What are some of the best practices used to prevent reverse engineering of software? Is it a major concern?
• Also is obfuscation/file permissions the only way to prevent unauthorized hacks on scripts? (call me a script-junky if you should)