Please be slightly more specific. I know Etched Sigil cannot proc Paralysis, and thus, not the Mandald Heal either. As for Firebird's, I don't believe it counts, elsewise I think a lot more Firebird's builds would incorporate it into the build, as it would be a much easier and cost much less to keep the bonus up while only channeling Disintegrate. It doesn't count for Tal'Rasha's set bonuses either.
The only thing I know for sure it counts towards is The Twisted Sword 's damage boosting of Energy Twister.
Most procs with ES don't work. The fire spells however are counted for the FB set - i actually ran an ES/AT firebird build with meteor spam but it was on the low side of dps. ET with twister sword does slightly better but the point is that TR+MH trumps everything else by a wide margin.
On the other side, it's an extremely fun build imho - just remeber: don't put multiple no cd skills in the bars because then ES becomes unreliable in casts.
ES prioritizes casts based on longest cd -> no cd. A good setup i found was Twister/meteor (based on preference) + EB + BH. Good CC plus easy time mainaing OoID buff.