Fire Strike and Brimstone questions

I’m now working on my dual pistols build and there are some points that are not clear to me.
1 - Do Brimstone fragments benefit from flat damage or is this damage only added to the initial Fire Strike hit?
2 - Can hits from Brimstone fragments produce further procs?
3 - Do Static Strike properties also affect Brimstone or is just the percentage fire part added?

I’d appreciate any feedback on my questions.

Thank you very much.

1 - Fragments don’t carry weapon damage so they don’t get flat damage bonuses
2 - No
3 - No on the lightning, the fire damage % is added I think but not sure

The damage you see on the skill of Brimstone gets added to your single target attack damage. It is also the only damage of the fragments themselves.

I’m pretty sure they can though.

Thanks a lot for your answers. In the meantime a few other questions came to my mind.
Does the lightning damage from Static Strike belong to the pool of procs?
And how about the knockback chance, is it in the same pool as attack procs or is there another pool for this kind of cc actions?

Thanks for clearing these up.