Two.crew? What if the person in the LHS is incapacitated? If you're doing charter work, a lot of companies require two pilots to be at the controls, to transport their personal. Should be all.
IR. Flying anywhere, for hire and reward apart from agricultural aviation, an Instrument Rating should be mandatory. Can get yourself out of a lot of trouble if caught in bad visibility, for example. It can get you into more trouble too, if you don't know what you're doing.