Comma Questions

Hi,
Okay, so my question is about commas. I understand the basic rules, but I question the following in a lot in fiction writing, which I realize takes liberties.

1.)
"He walked toward the house, and shouted his wife's name into the air. " - I see sentences like this a lot. Shouldn't the comma only be there if there is another subject following it. Doesn't the "and" without the comma connect two things this man does--"walked" and "shouted"?

"He walked toward the house, and he shouted his wife's name into the air." - I understand the comma here.

2.)
"He walked to the house, then shouted his wife's name into the air." --I see this a lot too. Do you use a comma followed by "then" or do you not use a comma. Or, do you use a comma followed by "and then" I don't see "and then" often in fiction writing.

3.)
"He looked at his wife, sleeping in bed with her lover." -- Do you always use a comma before the -ing construction in these situations?

4.) Lastly, does the position of words around "and" ever imply order such as in: "I jogged and lifted weights." How could I imply order--use the word "then"?

Thank you for any and all help. It is so appreciated.