@B1aderunner The issues you mentioned are on wunderground's side. Look at the xml pages the wunderground script is pulling from:
weather: http://www.wunderground.com/auto/wui/geo/WXCurrentObXML/index.xml?query=90210
Forcast: http://www.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=90210
You will see that heat index shows up there as N/A. Not much I can do about that. Sorry.
As for the forecast. It has to do with the detailed forcast, vs the simple forecast tags. It always gets a bit screwed up towards the evening hours local time. I haven't found a fix for that.
As for the wind speed. It only comes in MPH (see tag) In your msg $chan part, you will just need to do some calculation to get it correct.
var %wu_wind_kmh = %wu_wind_mph * 1.609344