Regarding the planned critical item changes, what i would do
i will preface this that i am not part of the balance team or even use champions based off of crit, but because of recent Youtube criticisms and input on my reply to the Dev Corner post i decided i would make changes i would think would work and be interesting .
i know it can use some tuning, its just a direction i'd prob prefer.
This would have 3 zeal items, 3 cloak items, and more AD centric options for critical items.
Then possibly of having unique crit type items like: stormrazer and a possibility one or two new items.
10% unique Critical
20% Unique Critical (price unchanged)
Cloak of Agility: +20% Critical Chance, Cost 800 Gold
Zeal (1300 Gold) + Long Sword (350 Gold) + Dagger (300 Gold) + 850 Gold
+30% Attack Speed
+30 Attack Damage
+20% Unique Critical, +10% Critical
+7% Movement Speed
UNIQUE – FIRECANNON: Your next basic attack gains 40% increased range (up to a maximum of +175 range) and deals 60 − 125 (+15% Bonus AD) (based on level) bonus magic damage on-hit.
Zeal (1300 Gold) + Kirchels Shard (600 Gold) + 900 Gold
+35% Attack Speed
+20% Unique Critical, +10% Critical
+7% Movement Speed
Unique: SHIV LIGHTNING: Your next basic attack (on-attack) sparks lightning that bounces up to 5 units within 400 range of each other, dealing 75 − 140 (+10% Bonus AD) (based on level) bonus magic damage on-hit.
Zeal (1300 Gold) + Longsword (350 Gold) + Longsword (350 Gold) +800 Gold
+25% Attack Speed
+35 Attack Damage
+20% Unique Critical, +10% Critical
+7% Movement Speed
Unique: WIND'S FURY: Basic attacks fire additional bolts at up to 2 enemies near the primary target, each dealing 40% AD physical damage. Bolts can Critical strike icon critically strike and apply on-hit effects.
Pickaxe + Caulfields Warhammer + Clock of Agility + Gold
+60 Attack Damage
+25% Critical Chance
Unique Passive: +20% Cooldown Reduction Unique Passive: Basic Attacks refund 1.5% of your missing mana

Stinger (1100 gold) + Cloak of Agility (800 Gold) + 850 Gold
+35% Attack Speed
+25% Critical
+10% Cooldown Reduction
Unique Passive: after hitting an enemy champion you gain 8% increased movement speed for 3 seconds.
Unique Passive: Lifeline
BF Sword + Pickaxe + Cloak of Agility
+70 Attack Damage
+25% Critical Chance
UNIQUE: When Critical strike icon critically striking champions, converts 15% of critical strike damage to true damage.
Long Sword + Long Sword + 750 Gold
+20 Attack Damage
Unique: Last Whisperer +20% Armor Penetration
Last Whisperer + Executioners Calling + 550 Gold
+40 Attack Damage
Unique Passive: Last Whisperer +25% Armor Pen Unique Passive: Executioner
Last Whisperer + Pickaxe + 525 Gold
+40 Attack Damage
Unique Passive: Last Whisperer +35% Armor Pen
BF Sword + Caulfields Warhammer +550
+75 Attack Damage
+20% Cooldown Reduction
Unique Passive: New Essence Reaver Ripoff
Now onto my own item ideas for supplemental crit items or what something that supplement crit can look like.
There would be Stromrazor, Forgefire Bolt, and Tundratessen
Forgebolt: Serrated Dirk + Recurve Bow + Gold +45 AD +35% Attack Speed +20 Lethality
Unique Passive: upon moving and attacking you build up to 30% Crit Chance, upon dealing a critical strike this bonus is reset
Unique Passive: Basic Attacks deal +15 Physical Damage
Tundratessen: Recurve Bow + pickaxe + dagger + gold +40% attack speed +50 AD
Unique Passive: while you are above 70% Health you gain 20% Critical Chance
Unique Passive: each time you deal a critical strike you slow your enemy 10% for 3 seconds and this stacks up to 3 times.
Custom items listed are based off Volibear(stormrazer), Orrn (Forgebolt) and Anivia (Tundratessen)