Chariots: First of all, you should keep track of the number of wounds inflicted on a chariot _unit_, and remove a model each time the appropriate number of wounds have been inflicted. Don't track the wounds model by model - it's just way too fiddly. If the chariots are involved in close combat then models should be removed from the fighting ranks, you can't choose to 'take a model off the back', just as you can't with ordinary models. Once the combt has been resolved an unengaged chariot models can 'step up' to fill the gap left by a destroyed model.
Heavy Chariot Automatic Hits: Only chariot models that can fight cause automatic hits. They are bonus hits in addition to the normal hits the chariot scores.
Shooting And Pursuit Questions: Don's first set of answers to these pretty much hit the nail right on the head, so I won't go over them gain. The only thing I'll note in addition to what Don said is that troops that fire and flee can't shoot in their next turn as they have to rally.
Cheap Vs Crap: This is an intriguing discussion, and I'm looking forward to seeing how it develops.For the time being I'll just say that most of my experience in Warhammer tells me that large units of cheap troops *can* be very effective, but they need to be used carefully as they are very 'brittle', and therefore require a good player to get the most out of them. As a case in point last years WHGT was won by an all Goblin army, but this was as much down to Stephan Hess (their general) as it was to his troops.
That's all for now...
Jervis