How about a been there, doing that point of view?
When I first started engineering professionally, my mentors told me that if I needed anything more than a plain scientific calculator to figure out the primary designs, then I was probably doing something very wrong or very unique. Incidentally, he has a strong background in mathematics.
It is usually best to stay within the well known regions of design. If you're writing out equations for those regions instead of using rules of thumb, then you're far more likely to be wasting time and making mistakes. If you're heading off the beaten path into regions of design where few have been before, then yes, you'll need your understanding of mathematics, but you need to be absolutely certain of what you're doing and why you're forging ahead on your own.
In 27 years of practice in the field, I have had a few of those unique situations. But the actual math that you cite is not common in practical, hard-nosed, engineering. Either these functions are canned in a piece of software, or there are rules of thumb that you probably didn't know. Those rules of thumb typically also take tolerances and wear into account. If you're not leaving some margin for error in your designs, then you're doing what we call "Engineering with a VERY sharp pencil."
That said, without the mathematics foundation that you are learning, you'll have no clue where those rules of thumb came from; and thus you won't know where to expect those rules of thumb to break down. Eventually you will reach a point where they do break down. If you're a very responsible and practical engineer, you'll usually stay away from those regions of design. But sometimes there is a compelling reason to forge new designs into new territory. I've been there in a few situations over the last 27 years of my career.
To summarize: All those mathematical tools are VERY useful for understanding what you're doing. However, do not expect to be drawing out equations at every turn. Real engineering is done either with software, a plain old scientific calculator, or even a slide rule if you just want to make a point.
Enjoy the math. But don't forget the practical applications in physics. This is WHY you're studying that math in the first place.
Good Luck!