Can someone answer my Elementalist/Golem questions to save me from my so/so build planning?

Hi,

For this league, instead of doing my best to follow a particular build I wanted to try my hand at a less directed approach; I decided which skills I wanted to use, used the passives that I thought might synergize well, and went to town.

That has worked out... so/so.

I feel like the damage is there (using 5l flame wall and 6l blazing salvo) - at least potentially.

Before I go too far down this rabbit hole, since I'm far from an expert to say the least, I wanted to ask for some help.

1) I feel like if I get the Primordial Chain amulet + 2 (or more?) Primordial Eminence jewels I should be able to scale the buffs provided by the golems significantly. Basically I believe, from my research, that duplicates of these gems are allowed and DO stack. Correct?

2) Herald of Ash. It isn't super-clear to me what "If you kill an enemy, other enemies near them will be burned based on overkill damage" actually means. Is the burn tied to the portion of overkill damage that is physical damage (which, in my case, is none) or does physical damage only matter for this skill gem for the "gain 15% of your physical damage as extra fire damage" line?

3) Charges -- I currently have no way of generating ANY charges, and I feel like I'm doing something wrong. Can anyone suggest a reasonable way to generate either frenzy or power charges for me that doesn't involve a body item or weapon (both of those slots are spoken for)? Perhaps something on the passive tree reachable by a Witch?

4) Golems! They're new to me. Up this point levelling I've been using 4 flame golems, but as far as I can tell the number of each type I have is not changing anything so it seems like (since my goal is basically to use primordial jewels to magnify the effect of the golems) I should really be using a variety of these guys:

a) 1 flame (extra fire damage)
b) 1 chaos (physical mitigation
c) 1 lightning (cast speed)
d) 1 stone golem

5) A lot of my damage comes from ignite, which I'm trying to scale with The Searing Touch. Are there any other items that would help with that? My chest is currently Infernal Mantle, but that was mostly because a 6L for it was dirt cheap.

6) I feel defensively weak; the basic problem is that I have to stand still which is never a good thing in PoE. Additionally, I'm en Elementalist so I don't have fancy "blind everything near me" skills like a tricksters do. I am sure a portion of my issue is that I'm low level 77) with terrible gear, but if anyone has a suggestion for how I could maximize my defenses I would appreciate it.

If it helps to answer these questions, this is my profile (character is _fireFireFIRE_):

https://www.pathofexile.com/account/view-profile/TheRealDeria/characters