He has control over what he wants to have control over. He doesn't have my passwords, as he feels there is no need for him to have them. We have joint bank accounts, so in effect he has control there. Work is the stickiest thing, he'd like more control, primarily cos my boss is a troll bitch,and he'd like to do unspeakable, and very painful things to her, but sadly that's not very practical for us. Only safeword I have is 'Stop' but I've never had to use it.
As to hard limits, Master has pushed my soft limits, and now some are things I actively enjoy- our hard limits coincide so that issue hasn't arisen.
I'm bisexual, but he has no wish to involve anyone else in our relationship so it's irrelevant to him.
IMO, how much control is given up should be negotiated and agreed on, control can change as the relationship develops. It's what works for the people involved.