Hey, is 48 fhr needed on bvc in PvP? If so, is it a waste to use a couple scs to hit the bp or will the life/dmg loss not be worth it.

yes, use sc's to hit a bp, Fhr / Res example.

You can get away with 0 fhr for pubs tbh

you could go coa + 3x vita charms with 30% fhr and +60 base life or coa + 3x fhr charms with 42% fhr and never notice the difference between the two
fhr is a lot less important on a bvc than other chars owing to high life total, uninterruptible attack and short animations. A lot of attacks won't reach the threshold to fhr you, and -60 life will make more reach that threshold, and those stun/knockback attacks might gimp you so badly you can't cast either way so its not much difference

Its very rare to not have an assa ingame, Even necs stuns babas a lot, so go for coa/guilly/arreat/Valk 08 with 4 5/5scs or a Eod

As Piwah says, o fhr is total ok in most cases.
i'd keep a 48 fhr setup for pride ft5 tho