If you don’t have issues reaching depth then just squat however allows you to move the most weight, which coincidentally will probably be a stance that you feel comfortable in. If you are getting a pinch in the front of your hip then it could be hip impingement which can cause serious issues (bone spurs, torn labrum) if you keep squatting like that. The pinch could also be related to some sort of muscle issue, but if it’s only when you’re in a deep, narrow-stance squat then I would assume impingement.
Stuart McGill has a thing where with a bent knee you see in which position you can get the deepest hip flexion, but that’s more for people with poor mobility or hip impingement. Under normal circumstances, somewhere around shoulder width would be a starting point and you can try slightly closer or wider and see how it goes. If wider/closer feels better (and stronger) then go a little further again and so on, eventually you will either find a spot that doesn’t feel right or you can’t hit depth and that’s when you have gone too far.
As far as toe angle, you want your knees tracking over the outer portion of your foot, otherwise it puts a lot of strain on the knee joint and can cause problems over time. Very few people squat big weights with their toes pointed forward, but it’s not unheard of.
There is a site called “Squat University” that has a bunch of articles on stuff like this, you might want to check it out. The guy is a physical therapist and former national-level weightlifter, he seems to know what he is talking about. I recently started doing a couple things I got from his site myself.