1. Not really, he still wants to earn himself a place in the best squad he can be in, and the better he plays the further to the front he goes into the shop window. Lots can change in 2 years and people can be forgotten about (I'm not suggesting nobody will want him in 2 years if he does down tools, however some teams will lose interest, limiting his options).
2. It's not "paying" £750k a week, it's failing to gain £750k a week, there is a big difference.
3. We would have to find goals from elsewhere. But how many seasons before rom (in the past 15-20 years) have the words "if only we had a natural finisher" been uttered. Look at the teams above us, all of them have a 20 goals a season striker, minus Liverpool and even without their top scorer, Mane, they massively struggled.