Provided I can create some code or script... where would be the best place to insert it in SC 3.5 so when someone clicks on Google or PPal an email is sent to me with "Check your orders" or some such.

Google is very good about notifying me but PPal will not notify on an authorization, only a capture. Without my current proxy merchant (my current setup) I will have no notice of PPal orders from my new store.

I just want to know when someone has committed far enough to click pay.

Feel free to suggest alternatives.

I really can't advise you on that personally, but I can say be very careful here. Any editing of those scripts can cause many in foreseen issues. I would hate to see your shop completely fail in some way.

I know I don't want to mess things up. I was hoping there might be some key point I could use to trigger an external script so it would not be embedded. I know enough to know I don't know enough to go mucking around in the code.

Ahh well... something you can add to the Pro version