Your concerns....
While interesting, are not valid.
If a company use the internet for critical infrastructure, that doesn't empower the government to circumvent the Constitution to 'protect them'. Their protection was sacrificed by their choice.
See the laundry list of solutions provided here and other places about infrastructure changes.
As for your other concerns or scenarios, the end of the day, these are a collection of 'private networks'. The government does not own them.
As for the 2 Senators seeing it coming, well Nastradamus they ain't. Threats to critical infrastructure have been coming since 95/96.
The threat of bad things does not justify removing the delivery mechanism. We still have roads, and darn it they are the delivery mechanism for drunk drivers. So are cars!
Come on, get serious, fix the problem not the symptom.
