I am (currently) resolved that we are both never self-teaching as well as always self-teaching at the same time. We are never truly self-teaching because everything we do and learn comes from somewhere or somebody else. For example, you pick up a piece of Chopin's music to learn, and in its broadest sense, who is it that you are truly learning from ? From where are you getting information ? What is the difference between learning from somebody through hours of acquaintance with a piece of music they have composed, and having a formal teacher who has learned from ultimately the same source ? Even if you are "self-teaching", you are still learning from something or someone. There are of course practical answers in having a formal teacher, but one can see what I am meaning.
On the other side of the coin, nobody can make you learn anything. They can only provide opportunities for you to learn, the rest is always up to you. In this sense, I believe, one is always self teaching.
So whether to stay with a teacher or not, it's entirely personal. There comes a time when the *opportunities to learn* in whatever guise that may be,
are less (in either quantity or quality or both) with or without a specific formal teacher, than the alternative (whichever that may be). Either way, it is always your own conscience which decides this, and rest assured you are looking out for your own potential to bloom.
As far as the specific things you are working on, there are many, many opinions on the matter. Ultimately, no matter what anybody says or does, your own conscience is what must be convinced of its most useful path. I would say, very serious students are willing to look at a broad spectrum of opinions (so as not to miss anything useful

) and discern what is one's personal truth.
Just my two cents
m1469
