Technical question about Infernal Legion support Gem

I need to understand the clear behavior of the gem to maximise the damage.
The only information i have on the gem panel is that the minions undergoes 30% fire damage of his life.

It would be really nice if we could see the ignite damage directly to have a clear view of what effects affect the minion.

To be clearest as possible :

- The support gem damage is affected by minion life (it's obvious) --> base damage is 30% of maximum life of the minion.
- Is the damage considered here like produced by the minion or by me ?
- Is the support gem affected by the other support gem like Muster or feeding frenzy affecting ?
- The base zone distance is 2m, but is it affected by minions zone area increases in the skill tree?
- The base zone distance is 2m, but is it affected by gems increasing the zone area ?
- does the "% increase ignite magnitude" affect the damage of the gem?
- does the "%increase minions damage" skill tree affects the damage of this gem?
- does the "indrease fire damage" affects the damage of the gem ?+
- does pain offering (or any other offering) affects the gem ?
- Are the damages affected by gain %Fire damage for example
I hope i didn't forget anyhthing !
thank you in advance!