I'm aware of this, but the infrastructural camp tends to assume that it's obvious these effects outweigh the problems with infrastructure. I'm not certain. I think a hybrid between the vehicular and infrastructural approaches is necessary to get the benefits of both with minimal downsides. This means recognizing the problems with infrastructure and avoiding them.
This is a really interesting point. One of the things about where I live that I think I've taken for granted is that biking is pretty common. Not as common as driving, but at any given time you are very likely to see at least one bike on the road.
And, in general, cars do keep an eye out for bikes -- and they even do things like slow down to make room for bikes when the road gets narrow.
Unfortunately most people are not going to ride when they have to mix with cars. I'm willing to do it on low speed city streets, and in unprotected bike lanes at up to highway (55MPH) speeds when I have to, but the great majority of people won't, and won't allow their kids to do it either. Protected bike lanes are the gold standard, and that's what we should be aiming for.