I can't see how the Valkyrie's weapon systems can be more powerful
than a nuclear missile.  If that were the case, then Macross city
would have been destroyed on day one.

ahhh..but you see...those werent reflex missiles :)

So?  It doesn't change the fact that an Eva could actually shoot a
Valkyrie down.

if it could ever hit one moving at speeds in exceess of mac 4.5

I wouldn't be so sure about an Eva having no wings nor an internal
power source ...

it still cant fly fast enough :)

Anyway, has anyone thought of a situation where an Eva and a Valkyrie
might have a shootoff?

what valkyrie pilot would stand toe to toe with a 100m tall eva....just sit
in orbit and blow it to bits...or call in the macross :)