Death Mark is not heal blocking (apparently all healblocking doesn’t block heals, just reduces them, not sure what the coefficient is or whether it varies between heroes).
Rolling Thunder is always dealing its bonus damage - probably because the first hit causes enemies to stagger which counts them as out of cover for the bonus damage.
HHG I’ve played 15,000+ PVP games this summer and been closely observing what’s going on with my heroes. Shoot me a PM or something because it seems like you could use some help.
Edit: His plat is giving ‘Loyalty’ bonus HP to all squad members, regardless of their UAF status.