Questions about Revenge Tunes

I've never dabbled in any Revenge Tunes other than Crimson Veil before, so I need to know a few things.

1) What level of abuse is required for them to proc? I know that different levels of stun have different chances of activating a Revenge buff, but how much of a chance exactly?

2) Can Revenge buffs still be procced even when using an anti-stun feature like Crimson Veil (like Ivis' and Dracken's innate versions), similar to how Stun Regain goes crazy?

3) Are there any difference in how Clearance and Hyper Shot work as Revenge buffs, such as buff time and frequency?

Thanks in advance.

6/12/18 for soft/hard/spin
yes
no

Suguri wrote:

6/12/18 for soft/hard/spin
yes
no

...Well that was fast. Thanks.

Two more questions, before I forget about them:

4) What stun level does a hit during Crimson Veil count as?

5) Do the percentages stack with multiple tunes? As in 6/12/18 for one, 12/24/36 for two and 18/36/54 for three?

same as whatever it would've been
yes

Excellent, thanks Suguri.