1. make ninjutsu an on-gcd spell with a 20s cd (exactly like standard step) with two charges, still keeping mudra at 0.5s with no animation lock, so executing suiton would go gcd (2.5s) > ninjutsu (1s) > ten (0.5s) > chi (0.5s) > jin (0.5s) > suiton (1s) > gcd
2. make kassatsu reduce ninjutsu cd by 20s (similarly to how heat blast does for gauss round and ricochet except a full single charge instead of half of one), and make tcj unavailable while active and 30% buff/enhance next ninjutsu, same as now
3. make ten chi jin not reset ninjutsu cd but instead be a separate on-gcd spell with a 110s cd that replaces your mudra buttons temporarily with the ninjutsu actions you would get from pressing them (with 1s cds), while making the ninjutsu cd unavailable during it, so executing ten chi jin would be like gcd (2.5s) > ten ch jin (1s) > fuma (1s) > raiton (1s) > suiton (1s) > gcd
4. make trick attack a 5% vuln up with a 15s duration while increasing personal dps substantially
5. make all gcds generate 5 ninki, make all ninki spenders cost 50 ninki, and make mug and meisui both generate 25 ninki
6. rework bunshin to be a 20s duration buff that lands a shadow attack after every gcd attack for the next 7 gcd attacks, while doubling ninki generation from those attacks
7. rebalance all ninjutsu and tcj potencies to fit their new state as gcd actions, while making sure that suiton is 250 potency less than raiton (or a bit more potent than that, accounting for the extra 0.5s required to cast it) so that meisui is fully dps-neutral
8. balance their total rdps properly so the class is on par with other melee jobs
These are just ideas, obviously, but their implementation would make the ninja playstyle much less impacted by high ping and clipping and much less reliant on double-weaving, while still keeping a relatively high skill ceiling, with the slight change of focusing on moving around ninjutsu to be under buffs instead of focusing on minimizing holding ninjutsu
Additionally, trick having a 15s duration would reduce the reliance many other jobs have on double-weaving in order to fit things in trick, effectively lowering the effects of ping on other classes alongside ninja