is it possible to deactivate the PM arm?

[testmon]

hello,

lately i read here that DM's can on will give or take feats from a character.
now thing is, my char is a pale master and i kind of like the class and think it makes (the way at least i understand it, not some others) RP sense.

now the thing is, the arm, from an RP sense my character would not amputee her own arm of to replace it with another and i always found it kind of strange, 100 palemasters and everyone at a point gets the idea "hey i really should cut my arm off"

so my question would be, would it be ok to ask a DM to take away the arm-feats from my char and me RP'ing she never had one? i mean i would just gain RP benefit but would lose ingame power, so i think at that point it would be a fair trade.

[DM Carebear]

Handled.

[Xanfyrst]

Handled.

I'm looking for the 'how'.