Do I need a brow lift?

I agree that a browlift can improve the shape and give a more relaxed and pleasant appearance. because you appear to have a high forehead, and endoscopic technique is probably not the way to go because it can move the hairline higher. I would go with a hairline incision subcutaneous approach.

What you are looking for does make sense aesthetically.  A rounder hairline is more youthful and feminine appearing.  This could be accomplished with a hairline lowering forehead lift.  This requires a partial hairline incision over the forehead centered on each side over the...

Adding volume either with synthetic filler or natural fat transfer to the temple and lateral cheek area would help to soften the look.

What you have is almost certainly a normal contour of your forehead. Many males, in particular, will have a slight central forehead depression. Usually it is not noticeable. Often in very athletic bodies, it will be more obvious, usually, as you say, in certain light. Almost certainly not...

A two stage process, the first involving expansion of the forehead, could give you what you want without raising the eyebrows. You would have to undergo a 3 to 6 week period of distortion of your forehead which precedes the second and final procedure. 

I have never found suture suspension to be long lasting.  I have suspended brows with sutures after an endoscopic brow lift as additional support but wouldn't rely on just the sutures.  The needles used are like the Reverdin needles used in the past and suspending the brow is...