I've seen some people saying bleed is currently extremely powerful, but I have no idea if it's worth infusing or what level you would need in Arcane to make it worthwhile.
I've been using bleed on my Rapier, it's been pretty powerful so far even though I'm not scaled into Arcane. The base damage isn't that high as it's mainly going of my Dex but mobs are usually bled in about 3-5 hits at which point they take a nice chunk of extra damage, very handy on some of the more heavily armoured ones that have a big life pool.
For bossing it seems a mixed bag, Margit got destroyed when I went back to fight him, the bleed took about 15-20% off each time. I don't even think I needed to heal once. Some do seem to be immune or have high resistance though so you would definitely need a backup weapon for just raw damage.
I actually managed to find a Katana that was scaled for Dex, Str and Int, doing physical and magic damage whilst also having bleed as well, that seems to have been a pretty big upgrade for me so far. In terms of the ashes I've found several that alternate the scaling between Dex and Str, one for bleed and one for adding Int scaling and magic damage. None for elements found yet but no doubt there will be, I actually really like this new system, no more farming for very specific shards for the infusion and you can quickly change it with no penalty.