Consistency, itemization and summoners
Consistency:
Abilities that fizzle when caster dies: Nami's Q, Vel's E, Xerath's W, Draven's R, Sivir's Q, Gragas' Q Abilities that finish when caster dies: Ekko's Q, Viktor's E, Gnar's Q, Ahri's Q Question is, why? Can we have some consistency? "Boomerangs" should always fizzle when they reach their "peak" (or return if they are already returning), targeted AOEs should always land.
Itemization:
What if offensive items had only offensive passives and defensive items had defensive passives?
Every time we got offensively-oriented item with defensive passive/active, it was abused/broken. These items had no trade-offs as they gave everything, and they ended up weak-ish because of it.
- was built by every AD champion because it gave damage and hardcountered mages at the same time, nerfed multiple times
- was built by every midlaner because it gave substantial AP and extremely strong active. Heavily nerfed multiple times
- was built by most top laners and even ranged champions. Got its stats and passive gutted, decreased gold and slot efficiency
- ;)
- used to be #1 item on every top laner, as it gave everything. Tankiness, damage, waveclear... it bypassed armor, so top lane was decided by who finished Sunfire first. Nerfed multiple times
- was used by every AD carry, got its utility and stats gutted
Remember original Zhonya's Ring? +120 ability power UNIQUE: Increases ability power by 25%. UNIQUE ACTIVE - STASIS: Put yourself in Stasis icon stasis for 2 seconds, rendering yourself untargetable and invulnerable for the duration, but also unable to move, attack, cast spells, or use items during this time. 90 second cooldown.
It got broken down into 2 separate items because it was used on EVERY AP champion. It's the same as current problem with . It gave substantial damage potential AND very strong active.
Next, had 120 AP, 50 armor and its current active with 25% lower cooldown. It was nerfed into it's current state. Why? Because riot nerfed all other AP items, so Hourglass became really good as it gave high AP and strong defensive ability.
Let's look at actives of these items: 
. How are they different from
?
Couldn't we switch some of these actives to summoner spells?
Cleanse and Quicksilver do the same thing, Mikaels does it on target. What if we baked them all into single summoner ? Cleanse CC off targeted teammate or yourself. Boom. ** Zhonya's **could be easily made into stand-alone summoner spell that counters diving and enables certain champions to function, just like Flash does.
**Barrier **could become spell that works much like Fiora's Riposte, basically ignore everything for 0.75 seconds while allowing you do make actions. Its basically reactive and offensive Zhonyas.
...
What i suggest is to remove these actives and compensate items that carried them by less impactful actives or passives.
Having such impactful abilities tied to expensive items is very restrictive when it comes to actually playing the game.
For example, hardcounters 
. Every AP mage gets when facing , which basically invalidates him. If we rework into summoner spell, that AP champion would need to chose between having more kill pressure with ignite, ability to escape with flash or having zhonyas.
On the opposite, when champion relies on such powerful active, he's too binary. 
and 
feel really bad without , and they would gladly trade one of their summoners for it. If we had tied to item, 
would be totally useless without that item.
**Items should reinforce your gameplay, not enable it. **