For down, take a look at the Montbell Superior Down Parka. Only $200 and very close in specs to the Kuiu Super Down Ultra.
The Kenai would be my pick for synthetic. I have the vest and used it for a spring turkey hunt in Humboldt County last year and it was great. It is actually warmer than the...
I think you're on the right track. Rain shell for sure if only for when the wind starts howling.
Personally, I like Peloton 97 bottoms more than merino bottoms. If I need a second layer under my Attacks then it's cold enough that the 97s are the better option for me.
You asked about types: insulated, soft shell, or fleece.
If I could have only one, I would go with an "active insulation" vest. (I have the Kuiu Kenai.)
It's light to pack, I can wear it over baselayers and mid-layers when moving, and it is slim enough that is fits under a soft shell or puffy...
You might try a metatarsal pad attached to your current insole first.
I had that same kind of pain in my work boots and thought I needed more cushioned insole. The salesperson at the Red Wing store had me try an insole with a metatarsal pad and the pain in the ball of my foot never returned.
Have you tried a vest? I used my Kuiu birthday discount to pick up a Kenai vest that I'm trying out next week on my turkey hunt. The Peloton 240 vest might be worth trying too since you are layering it under FL leaf top.
I'm 5'11", 200lbs, with a 34" waist and 43" chest.
The de havilland jacket in large did not fit will at all. The arm openings were way too high and tight. As bad as it fit, the M5/M7 and Grumman all fit great in a large.
The de havilland pants in medium were way too tight in the hips and leg...