World boss "support credit"?
If you never do any damage, you won’t get credit. All you need to do is damage it for a few seconds. As long as you get contribution, you’ll get the rewards. It doesn’t matter if you get gold/silver/bronze. You can even show up at the last second and hit it a few times, which will usually get you gold contribution. A lot of people abuse this by tagging and running or showing up just for the ending.
I’m more concerned about getting downed myself while trying to res people around the Fire Elemental than I am about not getting credit. As long as ressing people isn’t the -only- thing you’re doing, it shouldn’t be a problem.
(If that’s -all- you’re doing, chances are good that you’re not contributing a ton. If there are -that- many players dying, to keep you occupied instead of spot revival, it’s probably a better use of time for them to respawn. You’re fighting against the river if you’re trying to res a bunch of dead people.)
I let the Mesmers and Thieves worry about rezzing people on the Fire Elemental. Any other class is just going to join them on the floor if they stop (especially since rezzing people often bugs and prevents you from dodging or using skills until the rez is complete or you hit esc).
No, this game only consider damage as contribution.