Hi Derrick -
I don't believe that setting a "To" property for the bundled MachIIEmailLog is possible. You have to define it in the logging config XML.
You could clone the bundled MachII.logging.loggers.EmailLog.Logger, rename it to something else, modify it to pull the appropriate email address as a property from the environment, and point to that as your email logger in the logging config XML.
The answer to question 2 is: you have to write the code yourself. The email logger will send an email each and every time an error message is generated. It's for this reason that we don't use the email logger in development but instead only turn it on in testing and production.
brian