Your broker should be able to answer these questions but:
Yes, generally speaking, with BMW, the ROI is good on MSD’s.
NY dealers cannot do MSD’s, residents can.
Return it locally
Not really, as long as you’re not the type of person who is going to severely mess up your car and cause lease end damage, but it’s not like you could get out of paying for it in most cases anyway.
It’s not a problem, if you lose a key you lose a key, you’re not going to let BMW put you in collections over it if you’re not using MSD’s, just something to be aware of.