saurik, thank you so much for responding in this thread. Your answers are very insightful. In regards to 4, I've always assumed that to an extent, Apple tolerates jailbreakers and doesn't put as much effort as they could into fixing the exploits (unless they're critical, like the PDF one.) What do you think?
Apple has a schedule by which they fix bugs; if an exploit is not "dangerous" (such as a remote web browser vulnerability), they do not seem to alter their schedule to fix it, even if it helps people jailbreak: they treat it like any other bug.
As an example, 5.1.1 was subject to Rocky Racoon for many months throughout the beta releases of 6.0. This exploit requires physical access to an unlocked (as in, not at the lock screen: PIN code already entered) device; once the device is unlocked, you can just use it, getting access to e-mails, the address book... whatever you'd like: it isn't really a serious security hazard to also be able to jailbreak it.
