POE 2 Feedback - Pathfinder balance

I've made it through what I think is the majority of Act 3, so I thought I'd provide some in-progress feedback.
Currently I'm playing a poison-ignite pathfinder and although I've ran into some problems, the class feels overall alright.
Below I'll list some of those problems, mostly core game related, and an additional one for pathfinder alone.

- First of all, to help ease build creation, please allow us to buy lower tier skill gems from vendors. For example, I'd like to use Contagion, but since I'm only getting tier 9 or 10 gems, I can't since the int requirement is too high, and I only care for the debuff spread, so a level 1 would be fine.

- While difficulty is fine, I kind of agree that having maybe 10% less health on bosses would help it feel less of a sponge fight while keeping the difficulty and focus requirement.

- Finally, for pathfinder alone, the "Enemies spread their most damaging poison in a 1.5m radius when they die" ascendancy feels completely useless, since Herald of Plague gives better radius and a slow to boot for just 30 spirit, while the double poison node feels too delayed, as you'll easily reach 6/7 poisons while being capped at 2 or 3, especially harmful during the second Trial. My suggestion is swapping them, or at least allowing the node and Herald of Plague to stack and transfer two debuffs instead of only one.

Other than these, I think the game feels great and I found it very enjoyable, so my congratulations on an amazing release!