There was a time when ISPs thought usb modems were the way to go, but they never
really caught on.

Do you own the modem or does Verizon? If your ISP owns it, is there any chance
that Verizon can't give you a modem with ethernet? If not, there service really
sucks and I would look at alternatives. If they will replace the modem, then you
will have more options. If not, then you must stick with connection sharing
which can work with Linux, but it is not the best solution as all computers rely
on the one computer.It would be better if the computer was one that was not used
much and prone to crashing. If you must go this route, then you should look at
getting an old computer and dedicating it for this purpose and install Linux
which is more secure and use it as a firewall as well.