How noticeable are premolars? I have to get 2 removed for Invisalign. I'm scared I'm going to look homeless.

I try to widen arches and not extract any teeth if it is possible. Ask your dentist to explain why you need to remove teeth before you have them extracted. There may be a great reason but only a small percentage of cases require extractions. 

A far better choice would be to utilize a DNA Appliance to grow your maxilla to make the premolars fit.   This will give you a fuller more attractive smile.  Removing the premolars increase your risk of chronic daily headaches, migraines, TMJ Disorders, Snoring and Sleep Apnea.There are two types of orthodontics, Expansion Orthodontics and contraction orthodontics.  You are almost always better off with expansion orthodontics.Ira L Shapira DDSDiplomat, American Academy of Pain ManagementDiplomate, American Board of Dental Sleep MedicineFellow and Regent, International College of CranioMandibular OrthopedicsChair, American Alliance of TMD OrganizationsThinkBetterLife.com