I was partly saying it in jest. BHX does have very good rail links and would be very usable if you lived near Euston or Watford. the only problem would be the silly train fares. Stansted is being downgraded quite a lot by ryanair who had 40% of there fleet based there.
BHX does need to show that it is growing to justiy any investment in extra runway length. Moving the A45 into a tunnel does not sound cheap. It would not be worth the bother for just a few flights per day.