Clarity needed for Blademaster (Sword Saint Archetype)

[Ashbury137]

So, the Blademaster gets "Blade Techniques" and "Combo Finishers."  Do these Blade Techniques all need to be successful attacks for the Combo Finishers to be made legal to activate?  It feels a bit strong that I can attack 3 times, miss with any or all of them, and then have my fourth attack be: 

[color=#000000][font=Times New Roman]Cross Slash (Ex):[/font][/color][color=#000000][font=Times New Roman] (Requires Slash → Slash → Slash) This combo finisher allows the blademaster to slash his opponent multiple times rending unseen cuts onto them. The blademaster makes a single melee attack as part of this combo finisher. If this attack hits, the blademaster deals triple weapon damage.[/font][/color]

It does not say anywhere that my Blade Techniques need to be successful hits, but I feel like it would kind of make sense with how strong some of the finishers are.

Also, would the damage of these abilities be multiplied by a critical hit? E.g. Cross Slash deal 12d6 damage on a critical hit with a greatsword. The normal increase to damage isn't stated as being "additional damage" or "precision damage" that usually does not get multiplied on a critical.

Thanks for any input.