Well it would be good but i don't think this is important right now. We use Countdowns and start using it on around 10 seconds, then we hide and have plenty of time left. Ninja has bigger issues atm.

Ninki Management:
Ninki Costs are 80 for Bunshin and Bhavacakra.
We generate 8 per GCD. This gives us 80 Ninki after 10 GCDs. We should not overcap it, so we got 2 more GCds before we do. So we use Bavacakra/Bunshin asap. We have no option in holding Ninki for Buff aligment.
Ninki generation reduce from 8 to 6 or a higher Nikni cap, maybe from 100 to 160 would be great.
Ninki cost reduce from 80 to 60 would also be nice.

High Ping/Clipping/Bunshin:
Even with a Ping of 30 i am clipping. Clipping is always as slight dps loss and also reduces the GCDs on Bunshin. From 8 possible Gcds it may happen that only 7 GCDs fit into the Bunshin window because of clipping.
Extending Bunshin from 15 to 16 seconds may correct this. Bunshin could also need some potency buffs or at least copy everything we do.
While we are using Raiton and Suiton most of the time we are perfoming 2 and 3 mudras signs, which result in mudra clipping. The easiest way to fix it would be to slow us down. But it would also be boring to be slow like a Drg.
Pretty sure Nin works fine on the Test Servers with low Ping, but this isn't the case for most of the players. Another option would be that Mudras will not end up as a Rabbit Medium when you press another GCDS. It could be like this: Spinning Edge> Ten(5 seconds until effect vanishes)> Gust Slash> Chi(5 seconds until effect vanishes)> Aeolian Edge > Raiton.

Meisui:
When Meisui came out i was wondering when to use it, how important this skill is etc. In the end it just fixes our Nikni flow back to normal for Bunshin and Trick Attack line up. And is also a DPS loss. I personaly use it only after TCJ. I use Mudra Suiton only for Trick Attack and otherwise i use Raiton. (On Single Target ofc) This skill could need a little change. Samurai lost Hagakure with 5.0 and got Ikishoten (50 out of 100 Kenki Flat) instead. Meisui should be like this also. 30 or 40 Ninki flat for us on 60 seconds cooldown. (The amount depends in the Ninki cost and generation changes.)

Potency Buffs:
We don't need much, but a bit overall. More important are the upper 3 changes.