There is a fine line between being self-confident and being full of yourself. It’s a spectrum. You can guess which side I fall onto — I often go out of my way in trying to not appear egotistical.
I also realize this is a at least partly a function of personality type. Some people need affirmation from others like a fish needs water. Others are happy to work in relative obscurity. Neither way is right or wrong. However, either way can be wrong if they are left unchecked.
Those characteristics are not directly related to being self-assured or bossy. Self-assured is almost always good. Bossy is almost always bad. But bossy people can get lots of things done!