What are the odds my mole will grow back and compare to the original?

I don't think you should have regrets. You should be happy that it did come back negative for any malignancies and the only way to know that, was to shave and biopsy it. So, no regrets. Over time, the discoloration will resolve. I personally don't think Scarguard does a darned thing, but feel free to use it. More importantly, make sure to use a good sunscreen on it because burning the new pink skin will make it discolored for longer. When I have patients who have a bit of discoloration from a shave biopsy or removal, I often suggest a few light IPL flashes or Cutera Laser Genesis to that area. It helps tremendously. If your office has this, ask if it's a possibility. Any area where something is removed has the potential to discolor and leave a scar. A dermatologic surgeon or cosmetic dermatologist will have the intention to leave behind the smallest possible marks, but any time there's a removal of any kind, it can scar. Follow postcare to the best of your abilities, and this will always help.

Skin color can take months to fade after a shave excision so please be patient. Shaving a mole on the side of the nose typically results in a minimal scar. If for any reason a shave excision does not heal as well as expected or the mole grows back, it can always be excised and sutured at that time, but in my experience this rarely happens.