quick question:

why can you PC regen but not deadpool's ridiculous regen?

Simple answer:

On your turn you can prob control YOUR rolls, so your attacks and BCF rolls, and break away rolls. You cannot prob control opponent's rolls, like impervious, or hyper senses.

While it is not your turn you can only prob control your opponent's rolls, and when it is a game with a single opponent, it is the same bag of stuff: attacks, BCF, break away, NOT impervious or hyper senses.

you roll for Ridiculous regen during your opponenet's turn, not your own.

There are a few rare circumstances where you could PC Deadpools Ridiculous Regeneration, the most common of which is if your Deadpool gets caught up in an Energy Explosion you set off. Then Deadpool's RR ability is occurring on your turn and you can PC it.

/high five. This man speaks the truth.

Also note that if you have multiple opponents, you are able to prob control things that you normally would not be able to, if they are attacking each other. Normally, you are not able to prob control impervious, for example, but if Opponent one hits Opponent two, you can prob control either opponent one's attack OR opponent two's impervious roll.

Please also note that this has barely anything to do with the nature of Deadpool's Ridiculous Regeneration Trait, and everything to do with the timing and wording of prob control.

That's not true. It's the same things you can normally PC because you can only PC the active opponent.

From the Blackest Night PAC:
On Opponent 1's turn you cannot force Opponent 2 to reroll.

i want hyper senses

This actually came up in a game at our venue once, with hilarity resulting. After I pointed out the same passage referenced by Questions, the judge's ruling was something like this:
You can't PC him.
Why not?
Because Tyler is a jerk.
(This was in a team-up match, where the judge's character attacked and missed, and his partner wanted to use PC on his attack. And in case anyone doubts the accuracy of the ruling, the judge was Harpua. )