I'm wondering if anyone can answer me just one simple question.
Does it matter that the environment, including the setup, OS, MySQL and PHP versions are completely different between a Production Server and a Development Server for developing web-based software depending entirely on databases, php and the usual web languages?
I kind of know the answer already - but I want someone with lots of experience to clarify it for me, and explain why. It would be very very much appreciated! Thank you.
Why is simple. You want to be able to reproduce a production error/bug on your development system. Having identical setups for both will eliminate a lot of possibilities that the problem lies in version differences.