Live to Local on MAMP, not working, outputting functions.php code

If it’s outputting some PHP from functions.php but not the whole file then likely you’ve just got mismatched PHP opening/closing tags – <?php and ?> somewhere, or potentially even mismatched string quotations.

You need to edit that file in a text editor and look carefully around the point it’s starting to output PHP for mismatched entities. A good editor that does PHP syntax highlighting will make this much easier.