Are There Non Surgical Ways for Bulbous Nose Tip?

Your observation about exercise and fluid shifts is correct.  This also applies to warm weather, sun exposure, altitude, etc.  Thicker skin has more limitation but time after time I have been able to prove many of my colleagues wrong and provide very nice improvements to patient's noses even with very thick skin.  But there are limitations.  A very well "defined" tip is not possible in people with very thick skin even surgically but significant improvements can be made in most cases.  Non surgical options are even more limited when it comes to the tip but placement of a few drops of Restylane to the tip can create more projection and and make it look more narrow.  Standard excisional rhinoplasty techniques will fail in people with thick skin.  

Everyone is interested in non-invasive ways to look better.  But in a tip that is already thick and bulbous, fillers just don't work.  The thick, sebaceous skin is non-elastic and will not respond well to volume being added under it with Restylane, Radiesse, or liquid silicone.  The best (and only) choice is surgery to achieve narrowing by increasing the underlying cartilage strength and forcing the tip to narrow.