QDoes hBP01-023〈Tokino Sora〉's Arts 'Not gonna stop' deal damage equal to the number of odd dice rolled?

ANo, as the Arts damage is dealt after rolling the die and it can be used again if the die roll is odd, multiple damage instances cannot happen at the same time.

QYour opponent rolls odd number for hBP01-023〈Tokino Sora〉's Arts 'Not gonna stop', and gets to use this Arts another time.

If you have hBP01-027〈Vestia Zeta〉 in collab position, when can you use gift 'V.7'?

AYou can choose to use the ability at either the first or second instance of damage from Arts 'Not gonna stop'.

■ If you use it at the first instance of damage
Roll a die with 'V.7' when the first instance of damage is taken, and resolve the effect. On the second instance of damage, as the [1/Turn] condition is not fulfilled, the damage is taken as is.

■ If you use it at the second instance of damage
Do not roll the die for the first instance of damage, and take it as is. Roll a die with 'V.7' when the second instance of damage is taken, and resolve the effect.

QIf an odd number is rolled with hBP01-023〈Tokino Sora〉's Arts 'Not gonna stop', can you use a different holomem's Arts before using 'Not gonna stop' again?

ANo, it cannot.
After dealing damage, if you use this Arts again, you cannot use another holomem's Arts in between.