This rash can occur as a result of the adhesive from the tape that as used to secure the splint. Although it is rather disforming to the nose the redness and swelling is short lived. Topical steroid cream, oral over the counter antihistamines (like Benadryl or Zyrtec), and cold compresses...
This weakness in the alar wall (above the nostril) is termed external valve collapse. To fix this or not depends on if you have any breathing difficulties. This will be addressed and repaired during a rhinoplasty. Best wishes!
While it is hard to say for sure without an exam, it appears that the bottom of your nasal septum is deviated to the left a bit. That creates the fullness on the left side which can often be improved with a well performed rhinoplasty. Same goes for the differences on your three quarter views....