Can an osteotomy give at least 1-1.5mm height to a nose bridge that is not deficient in height? (photos)

You need a comprehensive approach to rhinoplasty. Tip-plasty is a component, but everything is relative. A better supported tip in isolation is going to further highlight the dorsal deficiency. You have thick skin, particularly over the tip, so refinement of the tip should employ a build-up, not necessarily tear-down approach. It will take more structure to define the tip as a result of the skin, so onlay grafting will likely be necessary along with tip modification. Your columella is retracted and will need some support as well. Alar base excision all depends on how increasing the length/projection have impacted the base and is done last. Most importantly, you need to review your goals and the limitations of the procedure with your doctor. You can achieve a great outcome, but don't focus on just one part. No action in rhinoplasty exists in isolation-every move impacts the others, and a step-wise approach with an open rhinoplasty is the most reliable. 

Osteotomies will not increase bony bridge height, and very frequently height is diminished. Regardless, you would benefit from a open structural rhinoplasty to address all of your issues. 

As you know your nose is quite wide. Osteotomies will narrow the bridge Nicely and may increase the height of the bridge slightly but not for sure. You would also benefit from alar wedge excisions to narrow the nostril base. This involves cutting out a segment of the nostril where it meets the cheek. The are many photos of this on the web and you would be usual for this procedure.