no, it's not possible to map EVERY key to the pad.. i maxed out the given combination opportunities on the ps3 pad [same button layout / same amount of buttons], which is emulated as xbox360 pad via ds3tools anyways..
HOWEVER, you can map the most important functions to the pad + a little bit more, i almost never reach to the keyboard [except for Navlock Wingman's target and debug cam, basically], and i also have the landing gear toggle on a button combo..
Obvioulsy a HOTAS would play much better, but since mine broke down ages ago [before buying Elite] i prefer the ps3 pad over mouse / kb any day, that's for sure [not that mouse / kb was an option for xbox players but anyways].
I wouldnt get too involved into PvP fights, though i never tested that by now...