Roma as a nick for
Rosamund? No, I don't think it is farfetched. It's sort of on the same level as
Carly for
Caroline; and it's sweet and affectionate sounding in relation to
Rosamund. Only thing about it is, as you say, the Rome connection - but I think metropolis names are 'normal' enough you could use
Roma and not have it "mean" Rome.
Don't like
Romy / Romie, eh? I know what you mean - it takes a certain sort of girl (who's definitely NOT like the one in the film) to wear this name well. Have to see what she's like, I guess.
- chazda