Question about a few Mesmer skills

I was looking to do the Hell's Precipice mission and currently I'm a wammo, but was thinking of playing around with a W/Me build to use Mantra of Flame. The description for it reads:

For 30...78 seconds, whenever you take fire damage, the damage is reduced by 26...45% and you gain 2 Energy.

My 1st question is say I'm attacking a Burning Titan (which of course causes everyone next to it to catch fire) then do I only gain the 2 energy when I'm caught on fire or do I continue to 2 gain energy for the duration while I'm on fire? Can someone help to clear this up for me because it doesn't really make it clear to me? If you do gain 2 energy for the duration then is it (2 energy)/(per X amount of time)? Thanks for helping to clear this up.

Then I guess my second question would be if I do use a Mesmer secondary then what skills (or skill combos) would be better?

Use Mantra of Flame
Use Mantra of Frost (if Winter is used)
Use Elemental Resistance
Use Elemental Resistance (if Winter is used)
Use either of the above stance with Dolyak Signet and/or Watch Yourself???
Is there anything else I could use in conjunction with any of these stances to further improve defense? Thanks.

Thanks.

You only get +2 energy when you're hit with fire damage, which means you won't gain any energy whatsoever from Burning (a condition).

With that said, stances are useless against Burning Titans, who use Wild Blow to knock you out of your stance every 5 seconds. Keep that in mind when making your build.

Degen is not considered damage, and so has no 'type.' Even though it's degen by burning, it's not fire damage- and totally unaffected by Mantra of Flame. You'll gain energy and receive damage reduction when actually hit by flame attacks or spells.

Thanks for the replies. So it sounds like about the only defensive skill that may be affective would be Dolyak Signet and Watch Yourself then provided it is used at the right times. At least this seems to be the case when fighting the Titans anyway.