Buy your own cable modem. Buy your own router to connect to your cable modem, and use whatever dns servers you want. This saves money in the long run because you no longer pay for the equipment rental.

You’d need 10gb on the nas, switch, and computer, or the transfer speed will be equal to the slowest component between them. But whether you’d get that full performance comes down to the speed of the disk controllers on the nas. You either have to find some performance reviews of this exact nas, or cross your fingers when you test it out.