I've been using a hacked vita since the day the first exploit came out, PSN account attached for like a decade at this point, never a single issue ever.
I unlinked my account at one point, don't remember why, but I regret it because every time I launch a title it asks me to sign up for PSN, warns about not being able to get achievements, etc. Mildly annoying. Used it for years with a linked account and nothing ever happened.