#1 Fix the solar errors by getting the arialbd.ttf file into the location in the error message. That file should be found in the jpgraph download but is maybe in a different folder, or I’m sure there is one on your PC that you can use.
#2 All the units are set in the graphsconf.php file starting around line 80. Open it in any plain text editor, it is well commented, you should have no trouble finding and setting the units.
#3 Arizona time zone is problematic, I need to research that some more.