How Often am I likely to get involved in physical combat and conflict?

Honestly, rarely. The only time you, in all likelihood, will use any of your skills of either/or martial arts or self-defense is in a dojo contest, a tournament or other sportive event involving martial arts, etc. As to conflict, your going to find a lot of conflict in your life but it is really your choice whether that conflict ends up getting physical. You will not go one day without some form of conflict and how you deal with it will hugely effect whether physical conflict enters the picture or not.