This is a kind of "New True Scotsman" argument where, presumably, any example of an unsafe driving situation will be countered with with some failure of driver certification. Be specific. How many people do you think we should try to get off the road, in order to increase the speed limit (implicitly, by not enforcing the one we have now)? How should we select those people?

By looking at how other countries do it. In Germany you actually have to drive on the motorway at high speeds as part of your training . I have a friend who was told to drive at 120mph during his training, and the instructors argument was "the road is empty, the weather conditions are appropriate, and there is no speed limit on this stretch of the road,so you should know how to handle the car at those speeds". Yet in my own country I know people who have never driver faster than 40mph during their training, yet the legal motorway speed is 90mph. Are they ready for driving at those speeds? No, they are not.

And the argument "what about woman driving while talking on the phone, eating and tending to children??" is completely pointless, just like "what about drunk people driving??" - both of these groups of people should be banned from driving, as both pose a danger to safety on the road.

Sounds great. Tell me again how we ban the kinds of drivers who are likely to talk on the phone, eat, and tend to their children?

We don't ban them when they are likely, we ban them when we catch them doing it. Psychological tests complimenting the practical driving test would also be a good idea.