Need some help on mechanics of Replica Atziri's Acuity

Hi!

I am currently playing marauder and aiming primaly for use of Ignite.
Since it is my own little silly build and I have no idea how to utilize ignite correctly - my only way is to use Perfet Agony

Perfet Agony is quite a far from marauder and I am thinking of alternative ways to obtain it.

According to wiki there is only 2 ways to have Perfet Agony otherwise:
1) Skin of the lords
2) Replica Atziri's Acuity

I am looking for a second choise but I also do not understand how does it work?
Item's mod says:

"

You have Perfect Agony if you've dealt a Critical Strike recently

Does it mean that:
1) Initial hit that crits will not be affected by any perfect agony effects?
2) Initial hit that crits will recive normal crit multi?
3) Ignite coused by initial hit will not be affected by normal crit multi?

Main build related question:
If Initial hit that crits is the first component from skill Earthquake (not aftershock) will the second component (aftershock) be affected by Perfet Agony?
(my thoughts: First component crits and have normal crit multi -> recive Perfect Agony -> Second component crits and do not have crit multi -> Coused ignite affected by normal crit multi)

is it right or wrong?
Ty)