The MySQL errors are caused by not having your MySQL installation on the System Path. Typically the default location for MySQL will be:
C:\Program Files\MySQL\MySQL Server X.X\bin
Where X.X is your MySQL version.
As an aside, under Windows, I personally find Rapid Environment Editor an invaluable tool for editing my environment variables (no affiliation). You can also do this without third-party helpers from Control Panel > System > Advanced > Environment Variables as described in the MySQL docs here (but after you've done this a few times you might see why I prefer Rapid Environment editor!).
As for the Git errors, I too had this problem On Windows 7 Pro, despite having Git and Tortoise Git installed. To resolve, first double-check that \git\cmd is in your System Path and is correct (in the same way as per the instructions for MySQL indicated above). If it is but the heroku command line continues to insist that it isn't, your heroku toolbelt install may have become corrupted on Windows. Try removing your heroku toolbelt's AppData\Local\heroku\ folder and then reinstalling heroku toolbelt. Typically, that means removing:
[C:\Users\YourUserName]\AppData\Local\heroku\
Doing so fixed my Heroku command line and removed the phantom Git errors it was reporting.
Finally after reinstalling heroku toolbelt, I recommend invoking heroku update from the command line to update it to the latest version.