Removing Cartilage Graft from the Tip of the Nose to Make It 1 to 2mm Shorter

In short yes the graft can be removed and in some cases it can be done with local anesthesia.In certain cases the tip graft can be  crushed  and replaced to give a softer less visible appearance.  Best to speak to your surgeon and come up with a plan.  photos would be helpful.

ideally you should wait at least 6 months to see how the tip projection changes - what may look overly projected at 2-3 weeks may look great after a few months

Revision Rhinoplasty can be very challenging.  There are several details needed to answer your question.  Most importantly a photograph would be very helpful. Altering the tip graft will certainly change the appearance of your nose.  Unless you've lost complete trust in your initial surgeon, he or she may be in the best position to perform the revision.  If you are able to articulate your concerns you may be able to form a plan together.

If you are not able to work with your current surgeon, you will need to start the process of finding someone else who is experienced with revision rhinoplasty to help your contour your nose. 

Don't make your decision hastily.  Just because the first surgery wasn't completely successful doesn't mean your current surgeon can't help you.  Sometimes, a small secondary surgery can be helpful.

Good luck in your search for answers!