Is there a walkthrough or is one not needed to get a good ending with love interests?
there are walkthroughs, but you can save frequently, and there should be a menu that has your path progress. I forget which tab has it, but you'll know if you made the right choice depending on if the progress bar next to the route your going for has gone up or down. (Imo the routes arent difficult to get right fundamentally. It's just making sure you have enough points in the right stats when need be.)