Nice writeup, but I should point out that the LA County subway/light rail system is actually called "Metro Rail," not "Metrolink," which is the system of commuter rail lines extending from Ventura County down to Oceanside.
I'm pretty sure the Metrolink trains have bathrooms (on the lower level), but the Amtrak trains definitely do.
The article as a good point about the unfortunately named Anaheim Station on the Metro Blue Line. That's for Anaheim Street in Long Beach! Just remember: if you're going to Universal or Hollywood you only need to use the Red Line!
1) Metrolink is the commuter train, the subway and light rail is called Metrorail.
2) Red line trains run every 6 to 10 minutes until midnight; 20 minutes after midnight. The 15 minute headways have been eliminated.
Also, nobody need worry about eating or drinking on the train. It's not ticketed despite the posted fines.