Looking for Feedback on my White Wind Frostblades Assassin

PoB fork: https://pastebin.com/AwPTh4A1
(full notes and issues can be found in the PoB Notes)

This is an adapted version of Mathil's White Wind Frostblades Assassin. I originally built this to use Elemental Hit, but the clearing experience of Elemental Hit is nowhere near as nice as Frostblades. I believe I'll be able to switch the two out interchangeably, using Elemental Hit (with 2 combat focus jewels) for bossing.

Current issues with the build:
1.) Squishy. 3.3k life is far too low, I think it will survive much better at 4.3k+. Can handle red maps up to tier 11, but some bosses still 1 shot me when they aren't frozen in place.

I picked up Vaal Pact to help sustain, but that won't fix the 1 shots.

Lightning coil probably needs to be replaced. Trying to maintain the extra lightning resistance is causing me to use subpar equipment elsewhere, whereas I might be able to get more life. Any suggestions on a good alternative to lightning coil? I haven't played melee in a while and I'm not sure where the meta is on evasion chests.

2.) I need a source of onslaught (besides the flask). Suggestions?

3.) I hate casting frost bomb for the cold exposure. What are my other options for getting cold exposure?

4.) A fully leveled Ancestral Protector requires too much strength. I think I could swap my amulet out for a better one if I didn't need so much strength. Thinking about taking a lvl 13 Ancestral Protector instead.

5.) Am I missing any other jewels/uniques/etc. that work really well with Frost Blades? I'm already using two Fight for Survival unique jewels for the 15% cold pen.

Thanks for taking the time to read this, I'm open to other suggestions as well. My current budget is fairly low, I'm looking to make gear improvements in the 1-3 ex range at a time, although I'm willing to shoot for a more expensive chest piece if necessary. Also it's good to have some more expensive targets to shoot for.