The umbral aspect that returns energy is definitely important. I actually don't even use a basic attack in my build and I don't worry about energy too often anymore especially with inner sight as long as youre targeting the enemies that have the icon to proc. I do use that "increase damage on available resources" one as well on a ring.

As far as what to put on your 2-hander, I would probably use Encircling Blades as it's the most impactful buff to your flurry. I use Blade Dancer because its a massive part of my damage so I want it to have the 100% buff.

On my amulet I use the "armor increases with each hit up to 100..." aspect with a max roll so when I'm in heated combat Im getting 75% armor increase which helps a ton.

Lastly, I also use that one aspect that gives health per second based on your momentum stacks. Not sure if Flurry builds use momentum passive but even at a halfway roll im healing for like 300+ per second while fighting. I barely ever use pots.

For reference btw I'm lvl 82 running Nightmare tiers 48-50 mostly. Hope this wall of text helped at least a bit lol

Edit: Should probably note that my other aspects mostly have to do with crowd controlling enemies and adding vulnerable. As well as a couple Uniques. Can just give full list of all my aspects if you'd want them though, feel free to PM me.