IMO this , as well as all other aspects of the relationship has to be negotiated. Some people like to have full control over their partner, though, how practical and possible in every day life, that is, is another discussion. There are subs who enjoy and crave this kind of psychological control, I personally would not care to be at either end of that relationship.

Whether I’m being the Top or bottom, my ideal relationship is one of respect. Neither party can truly enjoy the interaction unless they understand needs and consider wishes of the other. As submissive I will expect my opinion to be heard and considered (of course this applies to the important stuff - not whether or not I deserve to be spanked :P ) .

As a Dominant, I wish to get the input from my partner, but retain the right to make the final decision.

In regard to addressing other people - that is again, personal preference. Some people consider Master / Mistress to be very personal, others take it more as a general title. Seeing other people in what ever role - again, depends on the pre-negotiated terms. If you have open relationship, or one that is meant only for the BDSM purposes, and can work out the schedule - as opposed to being in 24/7 relationship with someone - than it is possible to have any other kind of relationship in your free time.

Communication, negotiation … anything goes as long as everyone involved agrees and is not being harmed in process.