Both are the right things to do in my eyes. Once in a serious relationship at the start or at least once you know you have deep feelings for a person, then by all means find out each others thought on boundaries and such things, what do they see for themselves they may want to be doing. It just takes once discussion.
When the relationship really takes off and their is talk or thought of marriage, discuss it all once more. For we do change the way we think throughout the whole of our lives.
Once in marriage, then occasionally ask each other what do you see for the future, what are your goals and aims.
Talk and communication shows not only respect for one another, it often keeps marriages going good. You don't have to talk deep every five minutes, just do it yearly or so, and you really won't go far wrong and that other person will stay and remain the love of your life.
Your a wise man.