Guild Wars 2

What stats govern these traits, is it just power for the damage aspect and healing power for the healing part of the traits or what ?
Is it worth it to gear specifically for these traits or are they so weak they are not worth it in the long run ?

Power affects the damage, Healing Power affects the heal.
The increases are so minor that going Zealot/Cleric isn’t worth it; the traits on their own can still be very useful, though.

Depends.

Some scale with power for dmg, some don;t. Some scale with HP for healing and some don’t. Usually scaling is very low.

Good thing is it totally ignores armor and dmg reductions like protection

https://wiki.guildwars2.com/wiki/Vampiric_Presence

https://wiki.guildwars2.com/wiki/Vampiric_Rituals

https://wiki.guildwars2.com/wiki/Vampiric

Thanks for the info guys.