Seven will retain all implants, but none of their enhanced features will work properly. (We aren't necessarily up on every detail of her implants, so apply that as you see fit and if you have additional questions about something specific, just let us know.)
She will still need to regenerate, but it won't be something she chooses. A bot will find her at night and escort her willingly or not to the hospital where she will be made to regenerate. The hospital in this prison isn't really a place you can choose to go or not go. If they deem it appropriate they abduct escort you.