Gov is a short form for government. It's 2 chars shorter than the old "govt." with a period or one shorter than "govt" without a period. It should be pronounced long form, as "governmment". It's used in this exact way on Twitter. On micro-blogs, every character counts, hence dropping the t and period from govt.
From Twitter: I think we have, along with our own gov's manipulators, people paid by parties, volunteers for Rush, etc.
"Etc.", with a period included, means "and so on".
The period serves no purpose, and it is commonly dropped, particularly in places such as Twitter, where space is at a premium. The requirement for a period at the end in order to be proper needs to be dropped.
There are many names for colors, such as red, blue, green, orange, etc, but there are far more colors than there are names.