The inclusion of Manipulate is a bit anti-synergistic, but my guess is it's there to encourage using Sky Laughs at Waves only after you've entered Arcane Cascade, where it should (and they should make this more clear) allow you to avoid provoking a reaction. If you use it as the opening action of your turn/combat, then it has the balancing factor of provoking reaction.
I don't think the rest works as you describe though?
It still takes an action to go into Arcane Cascade to gain the Study's benefit. Additionally, the Conflux allows you to make a Strike (1 action), not a Spellstrike (2 actions). AFAIK those two aren't interchangeable, so you couldn't Conflux > Arcane Cascade > Spellstrike in a single turn.
Seems like they wanted these things to be done over subsequent turns. Something like:
Turn 1) 1 action spell > 1 action arcane cascade > 1 action conflux to move to target + strike (presumably w/o provoking enemy reaction)
Turn 2) 2 action spellstrike > reaction to move away (again w/o provoking enemy reaction) > last action for whatever