Yep...they have been asked plenty of times. No you only need to install one version of custom firmware. When you downgrade to 1.5 and upgrade to a custom firmware, its essentially the same as upgrading to that identical Sony firmware but with homebrew capabilities. And the 2 most common ones used are 3.03OE-C and 3.40OE-A. For ps1 emulation, 3.40OE-A is better. 3.40OE-A also plays more game(s). But 3.03OE-C is easier to customize as in, customizing the xmb. And there should be a readme included in the file you download that contains the custom firmware that will have instructions on how to upgrade. Or just briefly browse through the tutorial section here.
It's not the religion that causes wars, it's the men who use religion as a means to control people that do.
They call me tater salad.
