Por fa

[Caballero]

¿Se usa por "por favor" en español neutro o en español de España solamente?

(Does it sound neutral or like a Peninsularism?)

[Rusty]

The words are usually combined when written (porfa), but it's just as simple to write out the entire phrase. The abbreviation, in speech, is heard everywhere, and there are a couple of variations - porfa, porfi, porfas and porfis come to mind.

I believe the abbreviated forms to be very colloquial, and mostly used by children. Wait for a native speaker to confirm, but I would rule against using them in any formal setting.

[Luna Azul]

¿Se usa por "por favor" en español neutro o en español de España solamente?

(Does it sound neutral or like a Peninsularism?)

I guess it's used and understood everywhere. It's extremelly informal (not vulgar, though). Something you use with your close friends and siblings.. and that's about it.
.

[poli]

like what's the diff in English