[Concoction / Void Sphere] Ranger > Pathfinder, Build Help

Hello! I'm striking out on my own this league and attempting a build without using a guide. I'm taking my time with the leveling/progression and have just reached the Library in Sarn.
I figure being at the library is a good place to stop and ask some community advice since I've got all my current gem options right there.

I'm attempting a Concoction build - (IDK if poisonous or explosive) would be my best bet, yet. I plan to use Void Sphere as a utility skill later on.

I'm assuming I want to go Pathfinder sub-class for all the flask skills on offer.

I don't really want to do DOT damage with this build, so I'm wondering if I should swap over to Explosive Concoction instead of Poisonous?

Also, I'm not sure what the best strategy is for scaling concoction builds, so some assistance there would be nice in regards to Passive Tree notables, Support Gems... etc.

How about leveling uniques for concoction? This is my league-starter build, so cost-efficiency is an issue.

The furthest I've ever gone in the end-game is Red Maps, and the goal this league (with this build) is to get beyond that if I can.

Here is the PoB Community Fork link for the build so far...
https://pastebin.com/5VQb5AAa

Any tips/tricks/advice would be appreciated. If I get really stumped on something or hit a wall with progression I'll do some deeper research.

Thanks for your time!