The problem with these buffs is not what they do, but how long they do it for.
In the case of Bloodletting, there’s a measly 5 seconds of down time?
Near permanent CC(95% of cc’s) immunity for the entire party.
This isn’t balanced for PvE, much less PvP. Both the duration and cooldown need to be reduced drastically.
Strong buffs like these should be choices, not something you just maintain.
10s duration with 20s cd for both Bloodletting and Stone Skin would be more than enough for the skills to be ~incredibly~ strong.
Or drastically overhaul the classifications for CC’s. Mix them up so they range from rank 1-5.