are we able to tag mobs by gearing as a healer?

Will we do enough damage as a firebrand? do other healing classes tag mobs well?

damage isnt an issue with FB if you go the condi/healing route.

Radiance refresh f1, spam away.

Damage doesn't matter when you are tagging, as long as it's above 0. What you are after is area coverage, and you can get that with Tome of Justice and Radiance to recharge the Tome on kill.

As for other healers, it depends on the game mode. I can only assume that you are thinking of wvw, because if you have tagging in pve, you have no reason to be a healer. Ele can change their attunement to tag, druid can't tag with staff, I don't know what ventari rev builds like in wvw, but they can tag with hammer.

And like brutaly said, focus on condi+healing. I still believe firebrand can't be a healer, but if you feel like building one, use a stat combo that allows you to do condi damage.

Is a power-healer viable? By going with Shattered Aegis. That way, your allies tag for you when the aegis breaks, and you can do a bunch of quickness through the aegis-to-quickness trait.

I mean, you'd still be tagging with F1 and hammer symbols, probably, to also share protection, but it seems like you'd be able to hit most things in an event.

I remember people saying in the old forum that Shattered Aegis is bugged, and has a 0.2 power scaling instead of 1.0, so it might work, but it hurts its viability.