Not sure what you mean by 'Haley path', since Haley is unavoidable regardless of what you have the MC do with other girls.
Sandra is also unavoidable until you reach the point where you decide whether or not the MC should keep Sandra as a girlfriend or not. Up to that point, all girls are available. After it, if you choose to keep Sandra, you are prohibited from pursuing other girls (except Haley). If you choose to reject Sandra, she disappears from the game, but the previous rule about all other girls being available still applies.
So, as of the latest release there are two paths, one with Haley and Sandra only, and one with Haley and everyone BUT Sandra.