[2021] Talon's bugs have been stacking up for a very long while now

Talon has been bugged ever since his rework back in 2016. Although the bugs then weren't major, they haven't been properly addressed to this point and have been adding up to an unacceptable amount. The bugs go as follows, in the order of their importance:

1. Abilities visually apply a fake Blade's End (P) mark even if the ability is negated by a spell shield or Fiora's Parry. This has been occuring ever since Talon's rework in Patch V6.22.
2. Melee Noxian Diplomacy goes on cooldown as soon as it starts casting, before even dealing damage. This is wrong behavior for a single-targeted spell with a cast time, because when it's used on a target that becomes unavailable (death/invisibility/untargetability/stasis/out of range or sight/etc) in the process, it stays on cooldown. No other ability works in this counterintuitive and inconventional way. This has been occuring ever since Patch V11.1, when the ability was recoded in order to stack Tear of the Goddess.
3. Assassin's Path gets interrupted by displacements even when protected by a spell shield. This has been occuring ever since Talon's rework in Patch V6.22.
4. Shadow Assault's blades disappear when the target they are converging on goes untargetable or vanishes. This has been occuring ever since Talon's rework in Patch V6.22.
5. Ranged Noxian Diplomacy's cooldown is about 0.4 seconds longer than intended because its cooldown restarts from scratch when the ability deals damage. This has been occuring ever since Patch V11.1 when the ability was recoded in order to stack Tear of the Goddess.
6. Ranged Noxian Diplomacy does not follow mobility consistently. It either follows properly, doesn't follow at all or doesn't follow for the entire dash. However, it ALWAYS fails if Talon loses sight of the target. This has been occuring ever since Talon's rework in Patch V6.22.
7. Shadow Assault can be recasted via pressing Q even if Noxian Diplomacy is not available to use (for example when under hard CC). This has been occuring ever since Talon's rework in Patch V6.22.
8. Shadow Assault cancels movement input when used during Rake's cast time and also cancels melee Noxian Diplomacy's basic attack input when used during its cast time. This has been occuring ever since Patch V8.9's input buffering changes.
9. Assassin's Path sometimes puts walls close to the landing spot on cooldown. This has been occuring ever since Patch V8.10 when this ability had a bugfix.
10. The cooldown per level tooltips of Noxian Diplomacy and Assassin's Path do not get updated by Ability Haste. Plus, Assassin's Path's cooldown is 2 seconds, not matching the cooldown displayed by the tooltip, which notes "No Cooldown". This has been occuring ever since Patch V10.18 when tooltips were overhauled.
11. Shadow Assault's blades visually disperse in a smaller radius, then teleport to their intended position in their second animation. This has been occuring ever since Patch V9.2 when the ability was recorded to work with Sylas's Hijack.

The video below provides evidence, as well as reproduction steps of every bug listed above.

https://reddit.com/link/r2ti2o/video/ckthnkz6fz181/player

Thank you for reading/watching.