Could use some feedback on build

I'm still quite beginner, joined only during Heist, and mostly just messed around. But I like messing around with builds, not just following a guide, even if it means running into already solved problem head-on. So I'm preparing a build for 3.13 for my own purposes. It has to be fast to deploy since I won't be playing that much-at most, 10-20 hours of lazy gameplay per week, easy to play (specifically, I hate the "flask piano" kind of gameplay, so I'll be keeping at most one flask up most of the time) but still capable enough to reach over 1M DPS and enough health to be able to take a glancing blow from one of the boss "nukes" once in a while. Hopefully, that would make it viable for endgame, even though bosses like Shaper will take a some minutes to kill.

In Heist, I've tried, with some success, a sweep Champion with impale and bleeding stacking for that purpose, but never invested enough time, due to events, to drive it into endgame. With the Champion passives I've been using being nerfed in 3.13, I figured I might try out Slayer instead. Drop any bleeding focus, go with just impale, focus on frenzy charges, and by proxy endurance.

My main concern is how will this turn out in practice. I don't have much experience with endgame yet, either in fighting or gearing. When messing around in PoB, I've given myself limits-for all rare items only three affixes mostly T3-T2, only few T1, plus one crafted, so 4 total. At level 90, over 25k max hit taken for elemental damage, 20k for chaos/physical without flask active. Hopefully, that would be enough. At level 90, all that's left is to pick up Champion of the Cause to get me some wiggling room with mana when maneuvering around bosses, jewel sockets and few +5% HP minor passives. The PoB is with most stuff turned off except for basics with nearly 100% uptime, and warcries are not really essential so this build could easily go with just 4L on armor.

So my main questions: how easy is the gear in PoB to obtain? Is this build viable for some endgame bosses? Did I miss something obvious to boost it, and how could it be improved with Harvest crafting in 3.13?

PoB: https://pastebin.com/gAR3FLxL make sure you have community fork updated to 3.13.

Rare to see a (new) player that is willing to learn and try to create their own build. I hope the veterans see this and answer your question.
good luck!

COMING THROUGH! I'll try to be brief and leave some discovery to you.

1. You should definitely get jewel slots, they're efficient in most builds within 3 passive points.

2. Strength is a good stat, check how much life and DPS it gives.

3. Taking all nodes in a circle is mostly inefficient.

4. You could get a worm flask to keep up the "killed recently" and charges at bosses.

5. Endurance charges aren't good unless you're jugg.

6. Crit is good.

7. 5C rares but 1 mirror early league weapon? I'd halve the weapon DPS.

8. Slayer is the weakest ascendancy.

9. You have way too low life for a zero layered defences melee character.

10. Maximum life also increases your leech and leech is very easy to cap.

11. You need at least some specialization in some sort of defence layer.

Don't dream about Shaper before at least 1M DPS and 6K HP - even then it's a pain.
Don't dream about Sirus 4 before at least 3M DPS and 7K HP - even then it's a pain.
Don't dream about Sirus 8 before at least 5M DPS and 7K HP - even then it's a pain.

Alright...

1. Which jewels? I don't know that much to be able to guess what kind will be available at that stage.
2. At what cost? Where would you make the tradeoff?
3. At the two points I did it, I deemed the minor good enough since I need to buff up armor.
4. That's interesting, might do that. I've got Doedre's Elixir to give my charges a jolt when necessary, this could be alternative.
5. Since I get them at virtually no opportunity cost...why not?
6. Cost, cost, cost...that's the problem. I'd need to buff up accuracy by about 2k before even going into any crit node.
7. That's a mirror tier? Three T2 affixes only, no influence? ...huh. Dropped the affixes by a tier, still acceptable damage. Seriously, how would a budget weapon for this build look?
8. Updated for 3.13?
9. Basalt flask ramps up the physical reduction when necessary. I could drop all axe passives, stuff the points into Soul of Steel node and all those minor life passives, gets me 88% phys reduction with flask. DPS goes under 1M though because I won't have 100% impale without either Harvester of Foes or Forceful Skewering. How would you branch into another layer though in this build? Block is out of question for 2H, and I got 3.6k evasion which is nowhere near enough.
10. Leech is capped. I got one life affix at every rare except for weapon, and picking up most life passives in reach.
11. And how exactly? Physical reduction can be handled by flask, but I see no easy way to branch out into other layers.

And by the way, pain to survive or to kill? I won't be farming those, so I don't mind a long fight once in a while.

i will be sincere
since you don't have much experience in endgame, first go for a max block gladiator and build your confidence with that, then if you really wanna test bleeding then respec the gladiator for one that uses the bleeding ascendancies
do not overcomplicate about using bleeding or maximizing gear

if you never get past the bosses mechanics then no build will ever satisfy you
especially now with echoes which maven will throw up to 10 bosses at the same time at you