Profile Image:
Fiverr profile picture size should be at least 250 x 250 pixels
Gigs Image :
Recommended image size is 1280 x 769 px, 72 dpi
Minimum: 712 x 430 px , Maximum 4000 x 2416 px
https://help.fiverr.com/hc/en-us/articles/15863342952977-Gig-Images-General-Gig-image-guidelines
Long Story Short , Well Title , Detail Description , Understandable and Attractive Images and video . use only gig related tags. some Q.A . its take time for 1st order . share gig links on social sites and when get an order work hard .
No you don't need to do that , if someone did bad and not get caught its doesn't mean you are lucky as well . use your stuff even its not much good , customer prefer buyer own portfolio.