As a life-based build, and bad with trap mechanics, I constantly find myself dying in the Trials and in the Labyrinth. I realized the utility flasks I'm using for the rest of the game aren't helping me at all. What could be the best flask setup for a life-based build to run the Labyrinth, provided that I don't have troubles with mobs, but the traps freak me out?
I'm inclined to equip 5 Chemist's Divine Life flasks of Adrenaline, but maybe I'm missing some useful flask mods.
You can't use armor to reduce damage from traps that deal damage over time (saws, spinning spike pillars etc.) meaning any armor based utility flasks are not helpful in those cases. It's seems that any sources of physical damage reduction will help so try a basalt flask and note any difference here. The skill immortal call gives a short duration immunity to physical damage but it will not activate off of damage over time effects meaning you will have to cast it manually.
You can however use armor flasks for hit based traps such as guillotines or floor spike traps. Since these deal damage as a hit and not over time you can reduce their damage with armor. These traps also apply a short bleed effect so getting a cauterizing (remove bleed) flask can cancel out their damage past the initial hit.
Fire floors are reduced by fire resist so they are already the least dangerous of the trap types, but you can get a ruby flask to help mitigate damage even further.
If you would rather run and heal through traps I would get a 20% saturated divine flask of adrenaline to heal the most hp while increasing move speed. Saturated increases amount heal by 50% while also reducing duration by 33%. This evens out that it heals at the same rate as a standard divine flask but for a longer duration. Adrenaline as you know increases your movespeed by a percent amount.
If you are taking shorter bursts of trap damage you could get any standard eternal flask instead. These flasks heal faster but for a smaller amount. Alternatively use a catalysed divine flask which will double its healing per second and is slightly better than a standard eternal flask. Note that since Divine flasks have a higher base heal, quality will give better results than on an eternal flask.
Given that you can handle mobs easily, and traps are your only concern (although 2500 life does seem pretty squishy without some really effective mitigation...) I'd recommend having several flasks for the labyrinth.
The first flask you want is a quicksilver flask of adrenaline. The double speed boost is enough to allow you to escape any trap you misjudge the timing on. The alchemist prefix will give even more boost if you can roll/buy it, but it'll be expensive. The worst/cheapest roll runs 2c, and quickly approaches "offer only" territory.
The second flask you'll want is a life flask with a prefix that gives instant healing. Panicked, seething, and bubbling all work. For your suffix you'll want Staunching, since it stops bleed damage. I'd suggest bubbling as the best prefix, because it gives instant healing, but also some healing over time.
In contrast to VanBuzzKill's answer, I'd suggest not relying on a life flask of adrenaline. When a life flasks life (or mana flasks mana) regen effect ends, so do all the other bonuses it provides via affixes, therefore you should always try to have utility affixes on utility flasks in order to get the full duration. Staunching works for a life flask because you will be popping it as a panic flask anyway.
For your third flask, just copy the second.
#4 and #5 are up to you, but if traps are really really what scare you, instant heal flasks and more quicksilvers will never hurt.
A few notes on how flasks work: As noted above, useful suffix effects only last as long as the flask's base effect does, so life flasks and mana flasks are terrible choices for a utility suffix. Once your life or mana hits 100%, the flask effect ends. Any utility suffix such as bleeding immunity, curse immunity, resists, defenses, ele status immunity... should always be used via a utility flask so the duration of the boost won't unexpectedly expire.
Lastly, never forget about movement skills. a Brightbeak leap slam with faster attacks in your alternate weapon slot is just as effective an escape as a good quicksilver. Flamedash, blink arrow, whirling blades, lightning warp, and flicker strike can all also be good, if in a more situational manner.
2500 life at lvl 80???? You cannot ever fight izaro!
So assuming you only go into lab to tag along. 2-3 bleed removing life flasks are enough (not more than 1 bubbling/seething, those aren't that good for traps).
If you find yourself dying to traps, simplest thing is to go a little slower and not get hit. Most traps are highly avoidable. Having a movement skill like mirror arrow / lightning warp / leap slam are also a big help.