If you like it - do. I personally didnt like it too much, but one of my friends said i turned her really on...wouldn't do it though in your > 6th month....you will have other worries then ;)
Definitely not required.. some girls like it, some others (like me) aren't to crazy for it anymore.. I'd rather sleep.
No...It is not required. It is up to you and how you feel. A lot of people say to have sex at the end of your pregnancy to help induce it...It never worked for me though!!!