Mark,
I also have a Becker Mexico. I love the search function, you will too.
#2--No Connection is required here.
#3--No Connection is required here.
#6--This is a power antenna output, if your car is so equipped. This obviously isn't connected either if you have a standard mast antenna.
You probably know but the top speaker jack coming off the Becker Mexico Amp is the Right side lead.
#1,#4,#5,#7, are correct and can be connected as you had planned.
Good luck.
Tim Dunagan
1971 280SL