Isn't heard immunity impossible anyway with current vaccines regardless of the strain, since vaccinated people can still carry and transmit the virus? Herd immunity only works if you have sterilizing vaccines.
Yeah but (current) vaccines are not stopping the transmission anyway, so they don't decrease R at all. That's been abundantly demonstrated already. (which is what Israel is finding out now after vaccinating almost everyone).
The vaccine does slow the rate of infection even Delta, but 59.9% is the current percentage of fully vaccinated in Israel and that's good but it's far from everyone. Very far given the infectiousness of Delta.
Not at all. They are much less likely to get severe symptoms, which is not at all the same thing. There are several studies already in several countries showing that with Delta the viral load between infected vaccinated people and unvaccinated people is identical.
Actually, herd immunity works if it reduces the R0 to less than 1.
Obviously, the extinction happens a lot faster wit a vaccine as you describe that reduces R0 to zero, but an exponential decline will still result in extinction (barring other reservoirs).
