Home dudes gear swaps are ok, but really only for the charms. Do not put all those points in conviction. Use salvation and it only needs one point. You could use ur remaining points for upping your max resists. Every 2 points in resist fire/lite/cold will up your max resists by 1.
Life leech doesn’t help on a smiter. Bk ring seems an odd choice. A rare ring with a ton of stats and resists would be far more helpful imo. Upped HoZ is kinda good but exile would be even better if you put it in the correct base. I’m a cheap-ass and use a 120@res sacred Rondache or sacred targe (4x p diamond)
Smiters aren’t good at clearing a ton of baddies. With zeal you can target multiple dudes but you still, sorta, only hit one at a time. I think your gear is fine. If you’re only using a smiter, I would argue that the mini Ubers are even harder than uber trist.
One thing I’ve done is keep morrowalks in my inventory and I’ll switch em on and off for my goblin toes. When you’ve got the boneweave boots on you can precast lifetap on a particularly nasty group of baddies (like those witches in matrons den or a boss pack of doom knights in furnace of pain). Once they’re lifetapped you can zeal/smite to clear the whole group with no problem and hopefully another group will rush you and you’ll proc a free lifetap. Always target and lock on to the dudes who are lifetapped.
Watch a video of someone doing uber trist before you go for it. I always kill Mephisto first. And there’s a trick to get baal on you where he won’t spawn a million wraith/spectres. These guys can get you stuck in a corner because of their mana burn and eventually kill you.
Trick: go to the bottom of the map (while no one is aggro’d on you). There are three ruined buildings at the bottom of the map. Take your pally and put his chest flat against the ruined building that’s in the middle of those bottom three. As soon as you do this he will spawn 1 or 2 minions on you and baal will teleport onto you. Smite him!
You’ve got this! You’ve got all the best gear! It’s just experience and confidence that you’re lacking. Good luck!
Sad tale: my buddy lost his level 99 hc offline mosaic sin in Uber trist 2 years ago this week.

RIP SlapBerd!
Too long?