Under the Bonnet $_REQUEST

Hi,

The way my code has mutated, it currently appears sensible (for a couple of- perhaps misguided(?)- reasons) to forego using the $_POST variable and restrict all my interaction with the user's offerings to $_REQUEST.

So today's questions are:

1) I am aware CI uses $_REQUEST for input destined for Validation... are there other significant places where there is a distinction between $_POST and $_REQUEST?

2) Are there any reasons for my intentions being a really stupid idea?

3) As an aside, I'm also using $_SERVER variables directly in my code, and not from the $_REQUEST copy of it. Having done a superficial scan of the CI system code, it appears that $_SERVER is also used directly (and not via the $_REQUEST copy, as what is done for CI’s Validation)... so if I remove $_SERVER from PHP’s registration of $_REQUEST (which, in my current "default" setup does contain $_SERVER), it shouldn't have any untoward effects on CI, should it?

Any ideas and expert advice would be greatly appreciated, thanks.

Gary