No, this is not the case. You would simply qualify the word ffrind to specify that someone is a particularly good friend, .e.g. ffrind da/ ffrind da iawn.Perhaps the best understanding is that the loan word "ffrind" connotes the sense of one's "pal" or "chum", while "cyfaill" would be used for saying that someone is "a true friend"?
Yes...I hear that, although I often try to buck such trends in my own common speech if I regret the loss of a particular word enough to do so. I actually find myself using "fellow" fairly often in speaking ("man" appearing a bit formal when speaking offhandedly and referring to the third person) because I prefer the word to "guy", which is what is commonly used now in the U.S., and, "dude" sounds simply ridiculous most of the time (unless, of course, one is pinching a marijuana cigarette between one's thumb and forefinger). Another example would be that I will use, though quite less often than the aforementioned, "gay" to mean "happy" or 'lighthearted", though as all are aware, that word has come to be used almost exclusively to refer otherwise in our day. Regardless, thanks, analeeh, for "nudging me back on to the rails" as pertains to "cyfaill" and "ffrind".I'm not sure we use it to mean 'fellow' either any more (or that we use 'fellow' much in English either, to be honest).