Stop 'N' Swop is still a mystery...

[Ccd-ToF]

As for Blackeye, I honestly don't see how anyone just jumps to the assumption that he has anything to do with SNS. Just because he's useless automatically means he has to be involved with SNS or something?

Blackeye have Pink egg picture in his Rom. ^^

And correct me if I'm wrong, but Banjo Tooie was made after they scrapped the whole SNS thing

I hear that SnS was removed in the last minute because Nintendo disaproove "Hot swaping".

Maybe Rare decided Bottkles' Revenge was a bad idea, but they didn't have time to take the whole thing out so they just removed all means of unlocking it? And perhaps RSA was originally supposed to be in the game, but Rare didn't ever get to completely putting it in there for some reason?

Rare confirmed that Bottle Revenge have a link with SnS. For RSA I dont know but it is logic that removed area have a chance to have a link with SnS.

[BanjoPL]

RSA has a best chance to have a link with SnS.
Now in BT RSA exist only as text. Maybe RSA would need data from BK for activation.
Bottles' Revenge is already programmed in BT so BR don't need data from BK for unlocking.
I'm pretty sure that there is a way to unlock Bottles' Revenge without hacking.
BK3 Game Guide suggest that Rare found a way to included all 6 eggs and ice key in BT so they found a way to included cyan,green and red eggs too!