In real estate, the value of a property is often tied to the value of the rental income it could bring in, even if it's never been offered for rent.

'Rent seeking' doesn't refer to the same kind of 'rent', of course, but I think the analogy holds up pretty well. All Google has to do is turn a few screws, and the rest of us will have no choice but to sing whatever tune they call.

Because they can raise the rents anytime and everyone else just has to pay. See Google Maps pricing fiasco for a rather public example.

Profit-seeking with market power is rent-seeking.

I think it's very destructive of meaningful discussion to redefine a term of jargon in order to exploit the stigma of the original definition while talking about something else.

No, if you have market/pricing (empirical monopoly) power, profit-maximizing behavior is inherently rent-seeking by the standard definition.